9 Atoms and Molecules

THE CHEMICAL FORMULAE OF CALCIUM BUCARBONATE

• Ca(HCO3)2

• CaHCO3

• CaCO3

• Ca(OH)2

The combining power of an element is known as its …

which of the following statement is not correct ?

1. atoms are neutral

2. atoms are basic units of matter

3. atoms aggregate to form large molecules

4.atoms exist indepedently

• 1

• 3

• 2

• 4

the valency of nitogen in NH3

• 1

• 2

• 4

• 3

atomicity of chlorine and ozone

• monoatomic, triatomic

• diatomic, triatomic

• monoatomic , tetratomic

• both are monoatomic

An element X has 7 electrons in the outermost shell and forms ion with symbol

• X^-

• X^-2

• X^-5

• X^-3

WHCH OF THE FOLLOWING IS NOT CORRECTLY MATCHED

1. PHOSPHATE -PO₄^3-

2. NO₃^- NITRIDE

3. SO₄^2- SULPHATE

4. HYDRIDE - H^-

• 1

• 4

• 2

• 3

WRITE THE CHEMICAL FORMULA OF ALUMINIUM SULPHITE

• Al₂(SO₃)₃

• AlSO4

• AlS

• Al₂S₃

How would H2O be classified? Check all that apply.

• Atom

• Molecule

• Compound

How would O2 be qualified. Check all answers that apply.

• Atom

• Molecule

• Compound