0703-W074(H) Y9 CHEMISTRY REVISION

Which diagram represents the arrangement of the outer-shell electrons in a molecule of fluorine?

• A

• B

• C

• D

Comparing to the plotted graph X, which of the graph A, B, C or D shows the plotted graph for the following changes; half concentration of dilute hydrochloric acid and at lower temperature?

• A

• B

• C

• D

(i)

(ii)

(iii)

(iv)

(v)

• more

• less

Which is/are the observation for the reaction between copper carbonate and sulfuric acid?

• Blue powder disappear

• green powder disappear

• colourless solution turns clear blue

• no changes observed

• bubbles produced

An atom of nitrogen shared three electrons with three hydrogen atoms. There is a lone pair in nitrogen atom in order to achieve stabile arrangement.

Complete the arrangement of the outer-shell electrons in a molecule of ammonia (NH₃).

Magnesium lost two electrons to form magnesium ion.

Complete the diagram with appropriate charge of magnesium ion and the electrons arrangement in the shells.