The most electronegative element from the following elements is:

1. Magnesium
2. Chlorine
3. Aluminium
4. Sulphur

The reason for using Aluminium in the alloy duralumin is:

1. Aluminium is brittle.
2. Aluminium gives strength.
3. Aluminium brings lightness.
4. Aluminium lowers melting point.

A hydrocarbon which is a greenhouse gas is:

1. Acetylene
2. Ethylene
3. Ethane
4. Methane

Fill in the blanks with the choices given in brackets:

(i) Conversion of ethanol to ethene by the action of concentrated sulphuric acid is an example of …………… (dehydration/dehydrogenation/dehydrohalogenation)

(ii) When sodium chloride is heated with concentrated sulphuric acid below 200°C, one of the products formed is …………… (sodium hydrogen sulphate / sodium sulphate / chlorine)

(iii) Ammonia reacts with excess chlorine to form …………… (nitrogen / nitrogen trichloride / ammonium chloride)

(iv) Substitution reactions are characteristic reactions of …………… (alkynes / alkenes / alkanes)

(v) In Period 3, the most metallic element is …………… (sodium / magnesium / aluminium)