Group 4A

Elements of Group 4A

Let's begin by looking what what group 4A elements are.

The group 4A elements are the 4th column across when you ignore the transition metals. They are also called the "Carbon family" since carbon is the first of these elements.

Below is where these elements can be found on the periodic table:

Fig.1- Periodic table with group 4A marked

The elements in Group 4A are:

• Carbon (C)-Element 6
• Silicon (Si)-Element 14
• Germanium (Ge)-Element 32
• Tin (Sn)-Element 50
• Lead (Pb)-Element 82

There is another element called flerovium (Fl). It is a man-made element that is highly radioactive. While its properties and reactivity have been studied, the findings are not fully conclusive, which is why we won't be discussing it much.

Group 4A Properties

Group 4A contains elements of all three types: non-metal, metalloid/semimetal, and metal. Because of this, we will be dividing our discussion into sections. However, we are first going to talk about some general properties of group 4A elements.

1. Electron Configuration and oxidation state

• All the group 4A elements have the same general Electron Configuration for their 4 Valence Electrons: ns²np².

• Because of this, they all have the common oxidation state of +4 (lose 4 electrons). However, both tin and lead can have +2 oxidation states, where they lose their p-electrons.

2. Boiling points

• The boiling points of each element decrease as you down group 4A.

3. Atomic radius

• The atomic radius is the distance between the center of the nucleus and the outermost electron(s).

• As you move down group 4A, the atomic radius increases.

4. Ionization energy (energy it takes to remove one electron)

• As you move down group 4A, ionization energy decreases. However, lead's ionization energy is slightly larger than tin's

5. Electron affinity

• Electron affinity decreases as you move down the 4A group.

5. Reactions with hydrogen

• All group 4A elements react with hydrogen. They generally have the form EH₄, where "E" is a group 4A element.

6. Reactions with Oxygen

• All group 4A elements react with oxygen. They all have the general for EO2. Both lead and carbon can also form EO compounds.

7. Reactions with Group 17 elements (Halogens)

• All group 4A elements will react with the group 17 elements (F, Cl, Br, etc.). The elements form EX₄ compounds, where "X" is one of the Halogens.

Nonmetal in Group 4A

Carbon is the first of the group 4A elements and is the only nonmetal of the group.

Carbon is an incredibly important element. So much so that there is an entire branch of chemistry dedicated to it called Organic Chemistry. Carbon is the 4th most abundant element and is an essential element for life.

Since it is a non-metal, it mostly forms covalent bonds. Which are bonds where electrons are shared between elements instead of transferred from one to the other (i.e. ionic bonds). Carbon can come in many forms, such as Graphite and Diamond, as shown below.

Fig.2-Carbon as Graphite (left) and Diamond (right)

It also commonly forms compounds containing hydrogen (H₂), nitrogen (N₂), and oxygen (O₂).

Due to its many forms and compounds, carbon has a plethora of uses, such as:

• Steel making
• Pencils (graphite)
• Jewelry (diamond)
• Plastic materials
• Strong fibers

Semimetals in Group 4A

There are two metalloids/semimetals in group 4A. These are silicon and germanium.

Silicon is a grayish element with a metallic shine (seen below)

Fig.3-A piece of purified silicon (Public Domain).

Germanium looks very similar, as it is also a grayish solid with a metallic sheen.

Fig.4-A sample of crystalline germanium

Since they are metalloids, they tend to form Covalent Bond like carbon.

Both elements are commonly used as semiconductors, which act as intermediates between conductors and insulators. Because of this, they are often used in computers.

They both also react with hydrogen (H₂) and nitrogen (N₂). Both elements can form several different hydrides (hydrogen compounds), with two of the most common being GH₂ and G₂H₄ where "G" is silicon or germanium. As for the nitrogen compounds, they both can form nitrides with the formula G₃N_4.

Metals in Group 4A

Lastly, we have our metals: tin and lead Tin and lead are both soft, malleable, metals.

Tin is silvery-white:

Fig.5-Sample of tin (Public Domain)

However, tin is gray with a bluish tint:

Fig.6-Lead cube (Public domain)

Because of their metallic nature, they form ionic bonds.

They both commonly react with hydrogen and halogens (group 17). Since they have oxidation states of +2 and +4, they can form either MH₂ and MH₄ for hydrogen compounds (where M is tin or lead) and either MX₂ or MX₄ for halide compounds (where X is a halogen).

In addition, they also react with oxygen to form either MO or MO₂, depending on the oxidation state.

Tin is mainly used in alloys, which are mixtures of metals. Such alloys include bronze (95% copper and 5% tin) and dental plating (60% silver, 27% tin, and 13% copper).

Lead's applications have been largely phased out. Lead is poisonous, and it can accumulate in the body over time, causing many health problems such as anemia (lack of red blood cells) and infertility. Previously, it had been used in items such as paints, pencils, and batteries.