Question

In modern periodic table calcium (atomic no is 20)is surrounded by elements with atomic number is 12,19,21 &38
a) which of these have physical and chemical properties resembling calcium
b) the smallest atom
c) more non metallic than others

Answer 1

${\huge {\mathfrak {Answer :-}}}$

➡️ Out of these, Potassium (K) , atomic no. 19, resemble the chemical properties of Calcium.

That's it..

Answer 2

a) magnesium (12) & Stontium (38) have similar chemical and physical properties to that of calcium...but, potassium (19) has similar chemical properties to that of calcium.

b) magnesium- since down the group, the atomic size will increase...and across the period, it will decrease.

c) scandium- since across the period, the metallic property will decrease and down the group, the metallic property will increase.

HOPE THE HELPS!!