Substances are represented by —

A. an element symbol
Incorrect. Element symbols are used to represent elements.

B. a chemical formula
Correct! Chemical formulas are used to represent substances.

C. a chemical equation
Incorrect. Chemical equations are used to represent chemical reactions.

D. an atomic symbol
Incorrect. Chemical formulas are used to represent substances.

H₂SO₄ is the chemical formula for sulfuric acid. According to the formula, sulfuric acid contains which of the following elements? Click here to access the Periodic Table.

1. Hydrogen
2. Sodium
3. Sulfur
4. Oxygen

A. I and II only
Incorrect. Sulfuric acid does contain hydrogen but not sodium. The symbol for sodium is Na.

B. I, II and III only
Incorrect. Sulfuric acid does contain hydrogen and oxygen but not sodium.

C. I, III and IV only
Correct! Sulfuric acid contains the elements hydrogen, sulfur and oxygen.

D. I and IV only
Incorrect. Sulfuric acid does contain hydrogen and oxygen but what other element is in sulfuric acid?

The chemical formula for caffeine is C₈H₁₀N₄O₂. Which element has the most atoms in caffeine?
Click here to access the Periodic Table.

A. nitrogen
Incorrect. There are only 4 atoms of nitrogen in one molecule of caffeine.

B. oxygen
Incorrect. There are only 2 atoms of oxygen in one molecule of caffeine.

C. carbon
Incorrect. There are only 8 atoms of carbon in one molecule of caffeine.

D. hydrogen
Correct! There are 10 atoms of hydrogen in one molecule of caffeine.

Which of the following is the correct ratio of atoms in glucose sugar (C₆H₁₂O₆)?
Click here to access the Periodic Table.

A. 6 carbon, 12 hydrogen, 6 oxygen
Correct!

B. 1 carbon, 6 hydrogen, 12 oxygen
Incorrect. The subscripts after the element symbol tell us how many atoms there are of that particular element.

C. 6 carbon, 6 hydrogen, 12 oxygen
Incorrect. The subscripts after the element symbol tell us how many atoms there are of that particular element.

D. 6 carbon, 12 hydrogen, 12 oxygen
Incorrect. The subscripts after the element symbol tell us how many atoms there are of that particular element.

Which of the following formulas contain the most oxygen atoms?
Click here to access the Periodic Table.

A. H₂O
Incorrect. This chemical formula contains 1 oxygen atom.

B. H₂O₂
Incorrect. This chemical formula contains 2 oxygen atoms.

C. H₂SO₄
Correct! This chemical formula contains 4 oxygen atoms.

D. HO₂
Incorrect. This chemical formula contains 2 oxygen atoms.