Question

Which pair of atomic numbers represents s-block elements?

Solution

Correct option is

3, 12

 

3 = 1s2, 2s1  

12 = 1s2, 2s2, 2p6, 3s2   

Since, last electron enters in s-orbitals, these are s-block elements.

SIMILAR QUESTIONS

Q1

Which of the following pairs has both members of the same period of the Periodic Table? 

Q2

An element with atomic number 20 will be placed in which period of the Periodic Table? 

Q3

The elements with atomic numbers 9, 17, 35, 53, 85 are all

Q4

In which block does 106th element belong?

Q5

Which group of the Periodic Table does not contain only metals?

Q6

The elements having the electronic configuration

[kr] 4d10f14, 5s2p6d2, 6s2 belongs to which block

Q7

Mendeleef’s Periodic Table is upset by the fact that

Q8

If Aufbau rule is not followed, K-19 will be placed in

Q9

Which of the following has largest size?

Q10

Which of the following has largest ionic radius?