Chemical Formulas and Compounds

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 or molecule.

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 the compound. For example, in H2O, the '2' indicates there are two hydrogen atoms.

Front

What is the formula for barium iodide?

Back

BaI2

Front

What is the formula for potassium sulfide?

Back

K2S

Front

What is the formula when sodium and nitrogen combine?

Back

Na3N

Front

What is the formula for the compound that forms between strontium and bromine?

Back

SrBr2

Front

What is the formula when calcium and chlorine combine?

Back

CaCl2

Front

What is the significance of the chemical formula CaCl2?

Back

CaCl2 indicates that one calcium atom combines with two chlorine atoms to form calcium chloride.

Front

How do you determine the formula for a compound formed from two elements?

Back

To determine the formula, you need to know the valency of each element and combine them in a way that the total positive charge equals the total negative charge.

Front

What is the valency of sodium (Na)?

Back

The valency of sodium is +1.