Question

A compound has a formula “H2X”. X denotes a non-metal. State the following: [5]

1. The electronic configuration of X.

2. The valency of X.

3. The bonding present in ‘H2X’.

4. The bonding present in the compound formed between calcium [20Ca40] and ‘X’.

5. The formula of the compound formed between potassium [19K39]​

Answer 1

Answer:

1) 2,8,2

2) 2

3) covalent bond

4) CaX

    Ionic bond

5) KO

finally X must be Oxygen

Answer 2

1. Electronic Configuration of X :

$X_{8} : {1s}^{2} \: {2s}^{2} \: {2p}^{4}$

2. Valency of X :

• X will have a valency of 2 , because two hydrogen atoms (of valency 1) are getting attached to it.

3. Bonding in $H_{2}X$ is COVALENT BONDING. ( SEE DIAGRAM).

4. CaX has IONIC BONDING between $Ca^{+2}$ and $X_{2-}$

5. Potassium (K) has valency 1, so it's compound with X will be :

• Formula : $K_{2}X$

SO, ELEMENT X IS ACTUALLY OXYGEN (O) !