Question

This reference to elements of the periodic table with atomic number so from 3 to 18 . In the table below, some elements are shown by letters ; even though the letters are not the usual symbols of the elements of the elements. 3 4 5 6 7 8 910A BalanceEnquiry C D E F G H 11 12 13 14 15 16 17 18 I J K L M N O P ( a ) which of these is : a noble gases? a halogen ?an alkali metal ? an element with valency 4 ?

Answer 1

At first you have see the periodic table to find this answer. I am just going to answered it shortly.
Noble gas: 18=P (actually argon refers here with symbol)
A halogen : 17= O (actually fluorine)
Alkali metal : 11=I (actually sodium)
Element with valency 4 : 6=F (actually carbon)

Answer 2

a) A noble gas-H,P

Noble gases are neon, Argon

b)A halogen-GO

Halogns are flourine, chlorine

c)An alkali metal-A,I

Alkali metals are lithium and sodium

d)An element with valency 4-D,L

Element with tetravalency are carbon and silicon.