Chemical Formulas

Front

What is a chemical formula?

Back

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

Front

What does the subscript in a chemical formula indicate?

Back

The subscript in a chemical formula indicates the number of atoms of the element present in one molecule of the compound.

Front

How many atoms of magnesium are in Mg(NO₃)₂?

Back

1

Front

How many nitrate (NO₃) ions are in Mg(NO₃)₂?

Back

2

Front

What is a polyatomic ion?

Back

A polyatomic ion is a charged species (ion) composed of two or more atoms covalently bonded, that can be considered as a single unit.

Front

How many ammonium (NH₄) ions are in (NH₄)₃PO₄?

Back

3

Front

What does the dot in CuSO₄⋅5H₂O signify?

Back

The dot signifies that the compound CuSO₄ is associated with 5 water molecules, indicating it is a hydrate.

Front

How many water molecules are in CuSO₄⋅5H₂O?

Back

5

Front

How many total oxygen atoms are in CuSO₄⋅5H₂O?

Back

9 (4 from CuSO₄ and 5 from 5H₂O).

Front

What is the significance of parentheses in chemical formulas?

Back

Parentheses in chemical formulas indicate that the enclosed group of atoms is a distinct unit, and the subscript outside applies to all atoms within the parentheses.