Question

What is the ground-state electron configuration of the Al^3+ ion? a. 1s^2 2s^2 2p^6 3s^2 3p^4 b. 1s^2 2s^2 2p^6 3s^2 3p^1 c. 1s^2 2s^2 2p^3 d. 1s^2 2s^2 2p^1 e. 1s^2 2s^2 2p^6 Which of the following is the correct noble gas electron configuration for an ion of barium? a. [Kr]5s^2 4d^10 5p^6 6s^2 b. [Kr]5s^2 5p^6 c. [Kr]5s^2 4d^10 5p^6 6s^1 d. [Kr]5s^2 4d^10 5p^6 e. [Kr]5s^2 4d^10 5p^6 6s^2 6p^2 How many orbitals are possible when l = 0? a. 9 b. 1 c. 4 d. 16 e. 0

Answer 1

4) The atomic number of aluminium is 13

Al has an electronic configuration of 1s²2s²2p⁶3s²3p¹

For Al³⁺ atomic number becomes (13-3)=10

So, Al³⁺ has an electronic configuration of e) 1s²2s²2p⁶

5) The atomic number of barium is 56.

Ba has an electronic configuration of [Kr]5s²4d¹⁰5p⁶6s²

So, for Ba²⁺ (barium ion[54]) ,the electronic configuration will be d) [Kr]5s²4d¹⁰5p⁶ .

6) When l=0,the possible number of orbitals is b)1

The number of orbitals in a subshell is therefore 2(l) + 1.

when l=0,then 2 x0 + 1=1