The Six 4p Elements

The last six elements in period four are Gallium (Ga - 31), Germanium (Ge - 32), Arsenic (As - 33), Selenium (Se - 34), Bromine (Br - 35) and Krypton (Kr - 36). These elements are created when the 4p orbital is filled.

Gallium is in the same group as Aluminum but it melts at 85⁰F so is very soft at room temperature. It also is one of only a few substances, the most notable being water, that are more dense in a liquid state than as a solid.

Germanium is in Group 14 with Carbon and Silicon. It is considered a metalloid and is most frequently used in optical systems due to its high index of refraction.

Arsenic forms many toxic substances, most notably Arsenic Trioxide, which inhibits ATP production.

Selenium is a semiconductor with the unusual property of conducting electricity better in the light than in the dark, and is used in photocells. It is also a popular trace element in vitamin and mineral supplements, functioning as a cofactor for the reduction of antioxidant enzymes and plays a role in the functioning of the thyroid gland.

Bromine is in the same group as Chlorine, the halogens. It is a dark, reddish brown liquid at room temperature, covered by a layer of gaseous Bromine which is dark orange. It exists as Br₂. Bromine's primary use is in organobromine compounds as a flame retardant.

Krypton is a Noble gas. It does not stop Superman, that is Kryptonite an as yet undiscovered element with an atomic number of 126. Like the other noble gases, Krypton can be used in lighting and photography as it has a high number of spectral lines and a high light output.

This completes the first four periods of the Periodic Table and most of the biologically active elements. Next we will look at some specific individual elements of Period Five and up as well as several groups consisting of elements in periods four, five and six, including the precious metals.

Transition Metals

With each of the next ten elements in the fourth period, one more electron is added to the 3d orbital. These are the fourth period transition metals. They include some of the more commonly known metals. In this group are Scandium (Sc - 21), Titanium (Ti - 22), Vanadium (V - 23), Chromium (Cr - 24), Manganese (Mn - 25), Iron (Fe - 26), Cobalt (Co - 27), Nickel (Ni - 28), Copper (Cu - 29) and Zinc (Zn - 30). These metals can be used as pure elements but are more commonly used as alloys of two or more metallic elements.

Here are a few facts about each of these elements.

Scandium's only major application, only just discovered in the 1970s, is in Aluminum alloys where as little as 0.5% Scandium can significantly increase the strength of the Aluminum. Scandium, although not rare, is difficult to mine and prepare. It is sometimes included in with the Rare Earth elements.

Titanium can be alloyed with Iron, Aluminum, Vanadium, Molybdenum and other elements to produce strong lightweight alloys. It is highly corrosion resistant and has the highest strength-to-weight ratio of any metal. Titanium Dioxide (TiO₂) is the most widely used white pigment because of its brightness and very high refractive index.

Small amounts of Vanadium considerably increase the strength of steel. Vanadium steel was first used commercially in Henry Ford's Model-T.

Chromium is added to Iron to produce Stainless Steel. This form of steel does not rust due to the formation of a thin coat of Chromium Oxide on the surface.

Manganese is added in some formulations of Stainless Steel. One percent Manganese is added to Aluminum to produce an alloy with improved corrosion resistance. This is used to produce soda cans.

Iron is the most common element on Earth, forming much of Earth's core. Steel is Iron containing approximately 2% Carbon. Iron alloys with numerous other metals to produce a wide range of types and grades of steel with varying strength, corrosion resistance and flexibility. Iron is also necessary for life being the Oxygen carrier in Hemoglobin.

Cobalt is used in the preparation of wear-resistant and high-strength alloys. It is one of only three transition metals that are ferromagnetic, along with Iron and Nickel. Ferromagnetic means a substance that can be made permanently magnetic or is attracted by magnets. Cobalt Aluminate (CoAl₂O₄), commonly called cobalt blue, give a distinctive deep blue color to glass, ceramics, inks and paints.

Nickel is chiefly valuable for the alloys it forms. About 60% of the world's production is used in nickel-steels, in particular stainless steel. It is also ferromagnetic. The American five cent coin, the Nickel, currently contains 25% Nickel and 75% Copper.

Copper is a very ductile metal with high thermal and electrical conductivity. It is used in almost all forms of electrical and electronic products. It is in the same group, Group 11, with Gold and Silver and shares similar properties. Copper forms two well known alloys, Bronze (Copper and Tin) and Brass (Copper and Zinc). Bronze is particularly resistant to seawater corrosion and Brass has excellent acoustic properties and low friction. Although Copper should have a 4s², 3d⁹ configuration, one of the 4s electrons goes to the 3d to fill it, leaving the one unpaired electron in the 4s orbital. This electron shift, in all three natural group 11 elements, affects the formation of bonds.

Zinc's major application Is corrosion-resistant zinc plating of steel (hot-dip galvanizing). It is also an essential mineral. Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. It is found as the reactive metal of a number of important enzymes, such as alcohol dehydrogenase in humans.

As can be seen from this information, most of these metals are used in alloys of Iron or Aluminum. They add strength or corrosion resistance to the primary elemental metal. No one element is a perfect metal on its own. A small amount of another metal improves the overall quality of the final mixture.

In the Bible we find the value of forming an alloy, or relationship, with God Himself. In Philippians 4:13 it states: "I can do everything through Him who gives me strength.(NIV)" And Exodus 15:2a says: "The LORD is my strength and my song; he has become my salvation.(NIV)" Luke 12:21 says "Yes, a person is a fool to store up earthly wealth but not have a rich relationship with God. (NLT)"

We also become stronger when we form relationships with others and work together towards a common goal. From Ecclesiastes 4:12 "Though one may be overpowered, two can defend themselves. A cord of three strands is not quickly broken. (NIV)"

This Side of Heaven

Yesterday my youngest daughter had her first child. It was a day filled with anticipation, not just because it was her first but she was a week late and seemed to be having trouble with going into labor. Everyone was excited when she went in on Monday morning at 8:00am but the labor dragged out and at 1:10am Tuesday morning the doctor said she still had another 8 hours to go. Her mother and I left to get some sleep, not knowing when the call would come.

She and her husband were exhausted by the long ordeal and glad to get some rest as they, with nervous excitement, anxiously awaited their daughter's arrival. The call came at 6:30am that she was ready to push. I had to go to work and the hospital was on the way so I got ready and went to see them. I arrived just after 9:00am. The last text had said she was crowning! Then a picture as I went upstairs to Labor and Delivery. Neriah arrived at 9:12am. But something was wrong.

I went inside to see if I could go in to see them yet and there was my son-in-law in the hallway talking with the nurse and a small fragile figure was in an incubator beside him. I came up to ask and listen. She had swallowed some meconium tinged amniotic fluid as she was being delivered, a condition called MAS (Meconium Aspiration Syndrome). This was serious as she was having difficulty breathing and was being moved to NICU. She looked healthy but clearly was in distress, her chest hiccupping as she took each breath. They rushed her off with her dad behind her.

I went in to see my daughter. She looked much more comfortable now but had a worried look on her face. She knew the tiny baby inside her had struggled to enter the world and in doing so, stumbled a bit and now needed more than she could provide. My daughter longed to hold her, that initial bonding moment between the two being denied by the urgency of the situation. They hadn't even had time to weigh or measure her before rushing out.

My daughter, wanting to be strong, smiled and said she felt good. We talked about the delivery and the concern for the baby. Dad came back in the room and told us what the doctor had said. She needed to be observed for a time to be sure that her lungs would clear. It was precautionary at this time. Her vitals were within range and they had started Oxygen and an IV. We talked for a time and then I asked if we could go see her. The nurse said it should be OK so with Mom's blessing, Dad and I went off to see our tiny new family member.

Getting to NICU, we scrubbed and gowned and went in. Neriah looked so tiny in that large neonatal bed, with tubes in her arm and mouth and nose. She softly cried as she tried to move and she opened her eyes when Dad gently stroked her leg. He looked older now, this new responsibility firmly landing on his shoulders. I knew he was ready but when you first step into those new shoes, they feel so big. And with this added burden of MAS, he was clearly feeling the weight. I could see the love in his eyes for his baby daughter. He had been fully involved in the pregnancy, always attentive to Mom's needs and wanting to feel the kicks and hear the heartbeats. Now he was able to shower that love on her in person and she felt it too, responding to his voice and touch. He told her he loved her and prayed quietly for healing. It was a picture of God's love for us, imperfect and weak as we are, being touched by His love and us responding to that touch.

We are fearfully and wonderfully made, knit together in our mother's womb (Psalm 139:13-14). But this does not mean we will be perfect, without spot or blemish. This world is flawed, due to our sin, and things happen that we will not understand until we pass through the veil into His presence. But we know that ALL things work together for good to those who love God (Romans 8:28) and there is a purpose for this current struggle. We will take one day at a time and we will see the Glory of God in this trial one day. Suffering produces hope for the kingdom of God. "We can rejoice, too, when we run into problems and trials, for we know that they help us develop endurance. And endurance develops strength of character, and character strengthens our confident hope of salvation. And this hope will not lead to disappointment. For we know how dearly God loves us, because he has given us the Holy Spirit to fill our hearts with his love." (Romans 5:3-5 NLT)

All the while we pray for full restoration, "For nothing is impossible with God." (Luke 1:37 NIV).

It is too early to know the full outcome of this challenge to our newest family member and what the future will bring. I do know that God is in control and He will give us all the strength we need to carry our share of this load if we just trust in Him. Here is where Faith and Science come together. God has given us the knowledge to use His creation to improve the lives of those who need help. In my granddaughter's case, she needs Oxygen and IVs. She also needs mechanical aids that just a few years ago were not available. She has an improved chance to make it through this unscathed due to the scientific advances man has made. But her life and all of our lives are in God's hands and He will ultimately control the end result. He has given us tools to do our part in the greater work of His plan for our lives and we will trust Him for the rest.

Got Calcium?

The next fourth period element is Calcium (Ca - 20). It has a full 4s shell and is looking to share these two electrons to have a stable Argon configuration. Calcium most commonly exists in solution as Ca⁺². It is the fifth most abundant element on Earth, an Alkaline Earth like Magnesium and exists as a dull gray-silver metal. It oxidizes in air to form a coat of Calcium Oxide and reacts with water but not vigorously enough to spontaneously ignite the generated Hydrogen gas. When it does burn, it produces a characteristic brilliant orange-red flame.


Calcium is essential for living organisms, particularly in cell physiology and is a major material used in the mineralization of teeth, bones and shells. In bone, Calcium combines with Phosphate to form Hydroxylapatite with the formula Ca₅(PO₄)₃(OH). The OH group can be replaced by Fluoride, Chloride or Carbonate. Replacement with Fluoride can strengthen the Hydroxylapatite in tooth enamel, thus the use of Fluoride toothpastes. When in solution Calcium has almost no taste, being described as mildly salty or sour. Its solutions are also colorless.

Calcium Carbonate (CaCO₃), one of the most common Calcium salts, is known as lime and is the main component of limestone. It is used medically as an antacid as in Tums®. Calcium Sulfate (CaSO₄) is the main component of Plaster of Paris and blackboard chalk. Both of these Calcium salts can be found in Portland Cement. Calcium hypochlorite (Ca(OCl)₂) is used as a swimming pool disinfectant (solid Pool Chlorine tablets).

The most abundant isotope of Calcium, ⁴⁰Ca, has a nucleus of 20 protons and 20 neutrons. This is the heaviest stable isotope of any element containing an equal number of protons and neutrons.

Calcium salts exposed in surface rock formations of limestone and other minerals are dissolved through the effects of rain and snow runoff (chemical weathering) and Ca²⁺ ions are released into the ocean. Each of these Calcium ions ultimately removes one free CO₂ molecule and stores it in carbonate rocks formed on the ocean floor. This CO₂ will likely be bound up for hundreds of millions of years in these rocks. This weathering of Calcium from surface rocks thus scrubs CO₂ from the ocean and atmosphere, exerting a strong long-term effect on the climate.

In foods Calcium is found in Dairy products such as milk and cheese. It can also be found in nuts and seeds (like almonds and sesame), blackstrap molasses, beans, figs, collard greens, okra, broccoli, and kale as well as fortified products such as orange juice and soy milk. Dietary supplements are available of the Calcium salts Calcium Carbonate, Citrate, Phosphate and Lactate as well as chelated forms. The recommended daily intake of elemental Calcium for adults is 1000mg. Vitamin D is often added to calcium supplements because it indirectly increases Calcium absorption by increasing the synthesis of the intestinal proteins required to transport Calcium into the bloodstream.

In the body, Calcium is a mineral necessary for life. It plays an critical role in building stronger, denser bones early in life and keeping bones strong and healthy later in life. Besides bone, Calcium has other important uses such as neurotransmitter release and muscle contraction. In the electrical conduction system of the heart, calcium replaces Sodium as the mineral that depolarizes the cell, proliferating the action potential and initiating the beating of the heart. Long-term Calcium deficiency can lead to rickets (softening of the bones and deformities such as bowed legs), poor blood clotting and, in case of menopausal women, osteoporosis.

The most well known Calcium containing food is milk. We drink it at birth as our only source of nutrition (breast milk) and many people continue to consume it in one form or another (cow's milk, goat's milk, cheeses) for the rest of their lives. It is so vital to life that God compares knowledge of Him and His Word to mother's milk, essential for our spiritual nutrition.

1 Peter 2:1-3 - "Therefore, rid yourselves of all malice and all deceit, hypocrisy, envy, and slander of every kind. Like newborn babies, crave pure spiritual milk, so that by it you may grow up in your salvation, now that you have tasted that the Lord is good. (NIV)."

Sodium's Big Brother

So going back to the fourth period, lets look at some of the more interesting properties of the elements in this row. First we will look at Potassium, a very important element in living systems.


Potassium (K - 19) is an Alkali Metal, the next heavier element in the same group as Sodium and functions in a similar fashion as Sodium in the body. It gets the chemical symbol K from its Latin name Kalium. It oxidizes in air and reacts with water with sufficient heat to ignite the hydrogen gas that is produced, burning with a pink-purple flame. It is found most abundantly as potash, hence the name Potassium (POTASh).  Potash is Potassium Hydroxide (KOH) which is extremely toxic and corrosive. Potassium has one electron in the 4s shell, which it is eager to lose, to have the stable Argon configuration. Thus Potassium generally exists as a positive ion, either in solution or in a salt or mineral form. Pure Potassium is a low density, silvery metal. It can be cut easily with a knife and melts at about 146^oF.

Potassium's most common isotope contains 39 neutrons. Small quantities of ⁴⁰K occur naturally. The ⁴⁰K isotope is radioactive with a half life of over a billion years and is used to date some types of volcanic rocks. It also occurs naturally in foods and is the largest source of radioactivity in the body. It is the seventh most abundant element and is found in Granite and Feldspar.

In the body Potassium is a critical component of nerve function and transmission. It creates an electron action potential across the cell membrane via the Sodium-Potassium Pump. This pump uses ATP to move three sodium ions out of the cell and two potassium ions into the cell, thus creating an electrochemical gradient. This action potential moves along the cell membrane propagating the nerve impulse. Potassium is also important in muscle cells, helping to control the contraction and relaxation of the tissues.

A shortage of potassium in body fluids may cause a potentially fatal condition known as hypokalemia, typically resulting from vomiting, diarrhea or increased urination. Symptoms of Potassium deficiency include muscle weakness, ECG abnormalities, decreased reflex response and in severe cases respiratory paralysis and cardiac arrhythmias.

Sufficient Potassium can generally be consumed by eating a variety of foods. Potassium is present in most fruits, vegetables, meat and fish. Cases of Potassium deficiency are rare in healthy individuals. Foods rich in Potassium include bananas, parsley, dried milk, chocolate, almonds and pistachios, potatoes, avocados, soybeans, and bran.

Certain classes of diuretics (urine increasing drugs) which rid the body of sodium and water have the side effect of also causing potassium loss in urine. Lost Potassium can be replaced by taking a Salt substitute containing KCl. Potassium Chloride has a bitter taste, however, and this form of salt is not very palatable. Tablets and capsules with controlled release KCl are available. High concentrations of KCl can cause tissue damage so it needs to be released slowly to prevent this.

Potassium is also widely used as a fertilizer, since Potassium is essential for plants as well as animals. The next time you are at Home Depot, look on a bag of most commercial fertilizers and there will be a listing such as 10-10-10. This is the NPK rating. It tells you, in relative terms, how much Nitrogen, Phosphorus and Potassium is in that particular brand of fertilizer.

Finally, Potassium as potash (KOH) is a strong base and as such is used in industry to neutralize acids and control pH and is found in industrial cleaners. Potassium Chloride (KCl) is sometimes used in the United States for carrying out the death penalty via lethal injection.

The Final Four Periods

The next two periods, four and five, each add another eight elements to the Periodic Table filling the 4s and 4p, and the 5s and 5p shells respectively. But in addition to this, they each also fill a new orbital, the d shell. Each d shell contains ten more electrons and is filled after the s shell. For the fourth period the first two elements, Potassium and Calcium, fill the 4s shell. Then come ten transitional metals filling the 3d shell followed by six elements filling the 4p shell. The fifth period follows the same pattern.

Not all of the elements in the fourth period have biological activity. Potassium (K - 19) and Calcium (Ca - 20) are essential to life. Of the ten transitional metals, most are considered trace elements or minerals (as consumed naturally) with the exception of Iron (Fe - 26) which is essential for Oxygen transport and cellular respiration. The remaining six elements are also mostly biologically active to a small degree with the exception of Arsenic, which is extremely toxic, and Krypton which is an un-reactive Noble Gas.

In the fifth period most of the elements are only minimally biologically active with the exception of Iodine (I - 53). Several are considered trace elements which only appear to be needed when completely missing from the diet as when someone is feed intravenously with Total Parenteral Nutrition.

The sixth period contains most of the remaining natural elements. It also includes the inner transitional metals which have electrons filling the f shell. This shell contains 14 electrons. The seventh period is similar except that most of the elements are synthetic, existing only for extremely short half lives when generated by nuclear reactors or particle accelerators.

This completes the Periodic Table up to element 118, the highest discovered element, Ununoctium, a Group 18 element (Noble Gases). Only 3 to 4 atoms of this element have ever been produced so it is not known if it is a gas or has properties like those of the other Group 18 Noble Gases.

In the next series of articles I will cover some of the more well known elements in periods 4 through 7 as well as some interesting facts about the lesser known ones before going back to period 2 and looking at Carbon, Nitrogen, Oxygen and Hydrogen (period 1).

The Quiet Gas

Finally we come to the last element in the third Period, Argon (Ar - 18). It has a full 3p electron shell so it is very stable. Argon is a Noble Gas and as such does not significantly react with other elements. It has no known stable compounds at room temperature, nor does it form diatomic molecules with itself. The name Argon comes from the Greek and means "the inactive one". It was the first Noble Gas to be discovered, being isolated from the air in 1894.



Argon is the third most common gas in the atmosphere, being more common than Carbon Dioxide. It is present primarily as the isotope Ar-40 and comes from the decay of radioactive Potassium-40 (K-20) which has a half life of over 1 billion years. Potassium-Argon dating can be used to date very old rocks.

It is used primarily as an inert shielding gas in high temperature industrial processes. It produces a distinctive blue-green light and is used in some fluorescent light applications. Being so readily available in the atmosphere, it is relatively cheap and is used where an inert gas is needed. It has a low thermal conductivity so is also used to reduce heat transfer, as in dual pane windows where it is used to fill the space between the panes.

Argon, being highly inert, is used as a preservative. It is used to replace air in a number of applications such as aerosol cans for varnish and paint, sealed bottles containing high grade chemicals or pharmaceuticals, and wine barrels. Since 2001 it has replaced Helium as the gas used by the National Archives to retard decomposition of such important national documents as the Declaration of Independence and the Constitution. Being a larger atom, it does not leak as quickly as Helium from the sealed display cases.

Argon is also used to humanely euthanize poultry as it can replace the Oxygen in their systems causing suffocation and, being more inert than the reactive Oxygen it replaces, preserve the meat. In high concentrations it stays low to the ground since it is heavier than the other elements in the air allowing the chickens to breathe it in easily. For such an inert element Argon has quite a number of unique uses.

Accidental Asteroid?

Going back to fire and brimstone and the destruction of Sodom and Gomorrah, some think that since an asteroid (see Fire and Brimstone, July 2, 2011) came in and dropped shrapnel on Sodom that it was not an act of God. By science it can be determined when Sodom was destroyed and when the asteroid hit and its trajectory. These two events can be seen to have occurred at near the same time, close enough to be tied together. Does this make it a coincidence?

If you believe Genesis 1:1 then you have to believe that an asteroid entering the Earth's atmosphere can easily be controlled by the Creator. God is in control and intervenes into our lives to give us direction and to shape our destiny. We can move with His plan for us or work against it. Paul says "all things work together for good to those who love God (Romans 8:28a NKJV)." Abraham believed and Lot was a good man in a bad place so God touched the Universe to destroy a town but held it back until the nephew of a patriarch could be lifted out with a move of His hand.

Of Rain Drops and Redwoods

Moving off topic from the elements we have been discussing to a different set of "elements", namely the rain, some of the fullness of Creation can be seen in the events of my family's Independence Day weekend. This past weekend half of our composite family went to Sequoia National Park to escape the Inland Empire triple digit heat. Spending four days at Hume Lake with 10 adults and 11 kids can be exciting to say the least. But manifest in the visit was the presence of God in nature.

Natural beauty is all around you when traveling into the mountains. Green forests, towering peaks and peaceful lakes bring an appreciation for the handiwork of the Creator. The first day the weather was hot and in the low 90's. It seemed that the heat had followed us. Skies were clear with no sign of rain. Each of the next two days it did get cooler but still in the 80's during the day with not even a hint of rain but with some very light cloud cover.

On the third day, Independence Day, the clouds started to move in and by the afternoon there was significant coverage. While riding the zip line, thunder could be heard and the rain started. First a drizzle and then a shower. In a matter of minutes it was gone. The temperature had dropped into the low 70's with the overcast skies but it was still warm and the smell of musty socks filled the air as the rain was just enough to turn the dust into mud.

As quickly as the clouds had moved in, they moved out again and the sky cleared. The brief shower showed how the weather can change almost instantly and you need to be prepared. Things are always changing when you are out in God's creation, away from the man-made controlled environments of home and office, out where you have only the treetops to protect you.

The next day the clouds were moving in from the early morning, stretching over the mountain top as we enjoyed a breakfast at Inspiration Point. Even with this, rain was not expected and certainly not in the way it descended on us.
Leaving the lake we traveled into the Valley of the Giants. These massive Sequoia trees are absolutely awe inspiring to me. They truly show the magnificence of God. Hundreds of feet tall, Over one hundred feet in circumference and thousands of years old, they stand as guardians of the forest. They are truly one of God's finest. I could easily spend hours enjoying them, but not today.

Down in the middle of the forest, with all the little grand-kids, it started to rain. First a small drizzle but quickly turning into raindrops the size of peanuts. With just the right combination of weather, cold air up high and updrafts to keep the droplets suspended, the water would form into larger and larger drops until the weight was too much for the air to hold aloft. We had to grab the kids and run for what little cover we could find.

The temperature, in the low 70's just minutes ago, now plunged into the high 40's. Higher up the temperature dropped even further until the raindrops, being held up by the wind, started to freeze and form into hailstones the size of peas. The rain intensity increased significantly and the hail started to fall until the ground was covered white. Running for cover, we watched as God replenished the thirsty ground for His Giants and let us know He was watching over them. He put on a show for us with one of His simplest but most amazing compounds, Water.

Fire and Brimstone

"DEATH COMES UNEXPECTEDLY" was the opening line of Reverend Ford's sermon, played by Karl Malden, in the movie "Pollyanna". He went on to harangue the congregation with visions of hell fire and the wrath of God for their sins and damning behaviors. This was a classic example of "fire and brimstone" preaching. The reverend pours out his wrath on the people for not following God's commandments. God did pour forth fire and brimstone on Sodom and Gomorrah for their evil deeds. Gen 19:24 "Then the LORD rained brimstone and fire on Sodom and Gomorrah, from the LORD out of the heavens. (NKJV)" This was not His wrath but His judgment on a people whom He had given many an opportunity to change their ways.

Could it be that the real fire and brimstone showered on Sodom were none other than the next two elements in the Periodic Table, Phosphorus and Sulfur?



Brimstone is actually another name for Sulfur used by the Alchemists of old, before it was known to be an element. It was so named as it was found around the "brim" of volcanoes. It had its own symbol, a triangle which was the symbol of fire and a cross, and was considered the omnipresent spirit of life.


Sulfur, a solid, is in the same group as Oxygen. It reacts similar to Oxygen as well but due to its larger mass, can inhibit bonding when linked with hydrogen. One example is Hydrogen Sulfide (H2S) which is a gas whereas water (H2O) is a liquid due to the stronger hydrogen bonds between the water molecules.

Sulfur is flammable and when burned produces Sulfur Dioxide which has a strong suffocating smell. It can be found as a pure element naturally, with 30 known allotropes (pure forms of the same element that differ in physical structure), existing as sulfur molecules with several sulfur atoms connected in a ring. The most common form contains 8 atoms of sulfur, with other rings containing 6 or 7 atoms. Rings up to 18 atoms have been synthesized.

Sulfur is essential for life and is found in many important biological compounds. It is present in all proteins being found in the amino acids methionine and cysteine. Many Sulfur containing compounds are odoriferous. One of the most widely known is Hydrogen Sulfide (H2S) which has a very characteristic "rotten egg" smell. It is a very toxic, flammable gas.

Another unusual Sulfur compound is Dimethylsulfoxide (DMSO). It is a very strong solvent, able to dissolve both polar and non-polar compounds. It also is readily absorbed through the skin and transfers the taste of the dissolved substance to the tongue. By itself DSMO imparts a garlic like taste when applied to the skin.

So it is very likely that the real brimstone of the Bible was actually sulfur raining down from heaven, possibly from volcanic activity or a meteor shower. What about the "fire"?

There is evidence that the "fire and brimstone" of Sodom and Gomorrah could have come from an asteroid. Some scientists have found evidence from an ancient cuneiform tablet with writings describing an asteroid that may have struck the Earth in 3123 BC, passing close to the location of Sodom and finally coming to rest in what is now present day Austria. Such an impact could have produced the smoke, flames and "brimstone". Phosphorus compounds can exist on an asteroid and potentially burn as the asteroid enters the atmosphere.

So it is not clear that Phosphorus was the "fire" but it is very flammable nonetheless. It forms a tetrahedron molecule with four atoms (white Phosphorus) that then links to other tetrahedron molecules by breaking one internal bond and joining to the next molecule. This chain like structure is called red phosphorus. White Phosphorus is the most reactive and least stable form of Phosphorus. White Phosphorus burns very hot and produces a brilliant white light.
Phosphorus is in the same group as Nitrogen. It is a solid, however, and more reactive than Nitrogen in general. It also glows in the dark due to a chemical reaction with Oxygen on the surface of pure phosphorus that produces intermediary chemicals that emit light.

Phosphorus is relatively rare on Earth and there is speculation that some of the Phosphorus found has come from meteors impacting the Earth. Phosphorus is very essential to life. It is found in DNA, RNA, ATP and the phospholipids that form cell membranes. It is used as a fertilizer, an additive to detergents and is found in bones and teeth.