Counting Atoms in Chemical Compounds

Front

What is the chemical formula for a compound?

Back

A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using element symbols and numerical subscripts.

Front

How do you determine the number of atoms in a chemical formula?

Back

Count the number of each type of atom represented by the element symbols and their corresponding subscripts in the formula.

Front

What does a subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element that are present in the compound. For example, in H₂O, the '2' indicates there are two hydrogen atoms.

Front

What is the significance of parentheses in chemical formulas?

Back

Parentheses are used to indicate groups of atoms that are bonded together. The subscript outside the parentheses applies to all atoms within the parentheses.

Front

How many Nitrogen atoms are in H₂C₃O₄N₅?

Back

5

Front

How many Hydrogen atoms are in 3(NH₄)₂CrO₄?

Back

24

Front

How many Oxygen atoms are in Al₂(SO₄)₃?

Back

12

Front

How many atoms of Oxygen are in Fe(NO₃)₃?

Back

9

Front

How many elements are present in Mg₂As₃COHNi₂?

Back

6

Front

What is the difference between a compound and a mixture?

Back

A compound is a substance formed when two or more elements are chemically bonded together, while a mixture is a combination of two or more substances that are not chemically bonded.