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.