Understanding Molecules and Counting Atoms

What does the subscript in a chemical formula indicate?

• The temperature at which the molecule is stable

• The charge of the molecule

• The number of atoms of the element

• The type of bond between atoms

Which of the following is a diatomic molecule?

• Carbon dioxide

• Water

• Oxygen

• Glucose

What is the mnemonic to remember the seven diatomic elements?

• Hoff wrinkle seven

• Hoffman wrinkle

• Hoff wrinkle elements

• Hoff wrinkle

How many atoms are in a glucose molecule (C6H12O6)?

• 18

• 24

• 12

• 30

What does a coefficient in front of a chemical formula represent?

• The number of molecules

• The charge of the molecule

• The type of chemical reaction

• The temperature of the reaction

In the formula 3H2SO4, how many hydrogen atoms are present?

• 2

• 3

• 6

• 12

How do you calculate the number of atoms in a molecule with parentheses?

• Add the subscripts inside the parentheses

• Divide the subscript outside the parentheses by each element inside

• Multiply the subscript outside the parentheses by each element inside

• Ignore the parentheses

In the compound Al(OH)3, how many oxygen atoms are there?

• 4

• 3

• 2

• 1

What is the total number of atoms in 2Cu(NO3)2?

• 24

• 22

• 20

• 18

In the compound Al2(SO4)3, how many sulfur atoms are present?

• 4

• 6

• 2

• 3