Given below are two statements: 

Assertion (A): Beryllium carbonate is kept in the atmosphere of carbon dioxide.
Reason (R): Beryllium carbonate is unstable and decomposes to give beryllium oxide and carbon dioxide.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

 

BeO is more stable than BeCO3 due to the small size and high polarising power of Be2+.
As BeCO3 is unstable and BeO is more stable thus, when BeCO3 is kept in an atmosphere of CO2, a reversible process takes
place and the stability of BeCO3 increases.
The reaction is as follows:
BeCO3BeO+CO2