Question

PERIODIC CLASSIFICATION

Q1. On going through the modern periodic table it is seen that the elements Li, Be, B, C, N, O, F and Ne

belong to the period-2.

(a) Write down electronic configuration of all of them.

(b) Is the number of valence electrons same for all these elements?

(c) Is the number of shells the same in these?

Q2. An element has its electron configuration as 2,8,2. Now answer the following questions.

(a) What is the atomic number of this element?

(b) What is the group of this element?

(c) To which period does this element belong?

(d) With which of the following elements would this element resemble? (Atomic numbers are given in

the brackets)

N (7), Be (4), Ar (18), Cl (17)​


please solve it

Answer 1

Answer:

1a.

li= 2,1

be=2,2

b= 2,3

c=2,4

n=2,5

o=2,6

f=2,7

b.

no

c.

Yes

2a.

12

b.

alkaline earth metals

c.period 3

d.