Chemical Formulas and Valency ( Need your Periodic Table)

What is the chemical formula for water?

• NaCl

• H2O

• H2O2

• CO2

What is the valency of sodium?

• 1

• 2

• 1.5

• 3

Name the compound formed from magnesium and chlorine.

• Magnesium chloride (MgCl2)

• Magnesium oxide (MgO)

• Magnesium sulfate (MgSO4)

• Magnesium bromide (MgBr2)

Write the chemical formula for carbon dioxide.

• CO3

• CO2

• CO

• C2O

What is the valency of oxygen in compounds?

• 4

• 3

• 2

• 1

What is the chemical formula for sodium chloride?

• ClNa

• NaCl

• KCl

• Na2Cl

What is the valency of chlorine in compounds?

• 1

• 2

• 4

• 3

What is the valency of magnesium in compounds?

• 4

• 3

• 1

• 2

Name the compound formed from calcium and oxygen.

• Calcium oxide (CaO)

• Calcium carbonate (CaCO3)

• Calcium sulfate (CaSO4)

• Calcium chloride (CaCl2)

The formula of magnesium chloride is

• MgCl

• MgCl₂

• MgCl₃