High School Biology : Understanding Properties of Carbon

Study concepts, example questions & explanations for High School Biology

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Example Questions

Example Question #1 : Understanding Properties Of Carbon

All organic compounds contain which of the following elements? 

Possible Answers:

Carbon

Nitrogen 

Hydrogen

Sulfur 

Oxygen

Correct answer:

Carbon

Explanation:

Organic compounds are defined as solids, liquids, or gases whose molecular structure includes carbon. Inorganic compounds, in contrast, do not contain carbon. Organic compounds might contain other elements, like hydrogen and oxygen, but not all compounds need these other elements to be considered organic.

Example Question #2 : Understanding Properties Of Carbon

What are the four most abundant elements found in living organisms?

Possible Answers:

Carbon, phosphorous, hydrogen, oxygen

Hydrogen, carbon, oxygen, nitrogen

Carbon, hydrogen, oxygen, sulfur

Hydrogen, nitrogen, oxygen, iron

Hydrogen, carbon, sulfur, nitrogen

Correct answer:

Hydrogen, carbon, oxygen, nitrogen

Explanation:

Living organisms are primarily made up of organic molecules, which contain carbon. The six most prevalent elements in living organisms are carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur, in that order.

Carbon and hydrogen are found in the basic monomer structure of all biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids). Nitrogen is found in amino acids, which form proteins, and the nitrogenous bases in nucleic acids (DNA and RNA). Oxygen is found in all biological macromolecules. Phosphorous is found in nucleic acids and lipids, such as phospholipids in the cell membrane. Sulfur is found in cysteine, a specific amino acid.

Example Question #3 : Understanding Properties Of Carbon

Why does carbon tend to form four molecular bonds?

Possible Answers:

It accepts four electrons to become more stable

It has four valence electrons

It is highly electronegative

It donates four electrons to become more stable

It must balance its partial negative charge

Correct answer:

It has four valence electrons

Explanation:

Since carbon is in group IV of the periodic table, we know that it has four valence electrons. Most elements (with the exceptions of hydrogen and helium) are most stable when they have filled their valence shell with eight electrons. For carbon to fill its valence shell, it needs to make four covalent bonds. Remember that carbon is not very electronegative and only very rarely (if ever) forms ionic bonds. This means that carbon will not donate, nor accept electrons; rather it will share them with other atoms to form molecules.

Example Question #4 : Understanding Properties Of Carbon

One carbon atom has the ability to bind with __________ other atoms.

Possible Answers:

Correct answer:

Explanation:

Carbon has four electrons in its valence shell which means it needs four more to have a stable octet. This means that the maximum number of bonds it can form is four when each bond only contributes one electron to the relationship.

Example Question #2 : Understanding Properties Of Carbon

How many valence electrons does a carbon atom have?

Possible Answers:

2

8

4

6

3

Correct answer:

4

Explanation:

One of the reasons carbon is so ubiquitous in biological structures is the fact that it has four valence electrons, meaning it likes to form four bonds to complete an octet in its outer shell. Being able to form four bonds means that it can bind to multiple other atoms covalently and with high stability.

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