Question

Properties of the elements are given below.

Where would you locate the following elements in the periodic table?

(i) A soft metal stored under kerosene.

(ii) An element with variable (more than one) valency stored under water.

(iii) An element which is tetravalent and forms the basis of organic chemistry.

(iv) An element which is an inert gas with atomic number 2.

(v) An element whose thin oxide layer is used to make other elements corrosion-resistant by the process of ‘anodizing’.

Answer 1

Part 1: Sodium:-

1. Alkali metals are soft metals that are very reactive in contact with air and moisture. Example- Sodium(Na)
2. Sodium belongs to group 1, period 2.

Part 2: Phosphorus:-

1. Phosphorus(P) has variable valency which is 3 and 5.
2. It is only slightly soluble in water and hence is stored under water.
3. It belongs to group 15, period 3.

Part 3: Carbon:-

1. Carbon has a valency of 4 and hence is tetravalent.
2. It easily binds with other various elements and is the basis of organic chemistry.
3. It belongs to group 14, period 3.

Part 4: Helium:-

1. Helium is a noble gas(inert gas) and has atomic number 2.
2. It has 2 electrons in its valence shell and hence is in a duplet state.
3. It belongs to group 18, period 1.

Part 5: Aluminium:-

1. The oxide of Aluminium which is Aluminium Oxide is used to in order to make the other elements corrosion free by a process called ‘anodising’.
2. It belongs to group 13, period 3.

Final answer:-

(i) Sodium(group 1 period 2) is a soft metal stored under kerosene.

(ii) Phosphorus(group 15, period 3) is an element with variable (more than one) valency stored underwater.

(iii) Carbon(group 14, period 3) is tetravalent and forms the basis if organic chemistry.

(iv) Helium(group 18, period 1) is an inert gas with atomic number 2.

(v) Aluminium(group 13, period 3) is the element whose thin oxide layer is used to make other elements corrosion-resistant by the process of ‘anodising’.