Counting Atoms

Front

What is the chemical formula for water?

Back

H₂O

Front

How many atoms are in one molecule of H₂O?

Back

3 (2 Hydrogen and 1 Oxygen)

Front

What does the subscript in a chemical formula indicate?

Back

The number of atoms of the element in one molecule of the compound.

Front

How many total atoms are in the compound C₂H₈O?

Back

11 (2 Carbon, 8 Hydrogen, 1 Oxygen)

Front

What is the total number of elements in the compound C₂H₈O?

Back

3 (Carbon, Hydrogen, Oxygen)

Front

How do you determine the number of Nitrogen atoms in (NH₄)₂CrO₄?

Back

Multiply the subscript of Nitrogen (4) by the coefficient (2) to get 2 Nitrogen atoms.

Front

What is the significance of parentheses in chemical formulas?

Back

Parentheses indicate that the enclosed atoms are grouped together and may be multiplied by a coefficient.

Front

How many Oxygen atoms are in the compound (NH₄)₂CrO₄?

Back

4 (1 from CrO₄ and 0 from NH₄)

Front

What is the total number of atoms in (NH₄)₂CrO₄?

Back

12 (2 Nitrogen, 8 Hydrogen, 1 Chromium, 4 Oxygen)

Front

How do you calculate the number of atoms in a compound with multiple elements?

Back

Add the number of atoms of each element together.