Counting atoms

What is a number written in front of a chemical formula called?

• Coefficient

• Subscript

• Element Symbol

• Molar Mass

What is the purpose of a coefficient in a chemical equation?

• To indicate the number of molecules or moles of a substance.

• To balance the charges in a reaction.

• To represent the temperature of the reaction.

• To show the state of matter of the substances.

What are the numbers found on the lower right-hand side of an element symbol called?

• Subscript

• Superscript

• Coefficient

• Index

In the compound NH4Cl, how many nitrogen atoms are present?

• 0

• 1

• 2

• 3

What is the chemical formula for a compound containing 4 carbon atoms, 8 fluorine atoms, and 8 chlorine atoms?

• C4F8Cl2

• 4CF2Cl2

• C4F2Cl8

• C4F4Cl4

In the formula C6H12O6, how many hydrogen atoms are present?

• 6

• 10

• 12

• 14

How many oxygen atoms are in the compound Al(OH)3?

• 1

• 2

• 3

• 4

How do you determine the number of atoms of an element in a compound with parentheses?

• Add the subscripts of the elements inside the parentheses.

• Multiply the subscript outside the parentheses by the subscripts of the elements inside.

• Count the total number of elements inside the parentheses.

• Ignore the parentheses and count only the subscripts.

How many different elements are present in the compound H2COCH2?

• 2

• 3

• 4

• 5

What is the total number of atoms in the compound Ca(OH)2?

• 4 (1 Calcium, 2 Oxygen, 1 Hydrogen)

• 5 (1 Calcium, 2 Oxygen, 2 Hydrogen)

• 6 (1 Calcium, 3 Oxygen, 2 Hydrogen)

• 3 (1 Calcium, 1 Oxygen, 1 Hydrogen)