Question

iii) The atomic no.of element A is 11,and of element B is 20.Which element is more
reactive ? Write the reaction of element A with hydrochloric acid.​

Answer 1

Answer:

atomic number 11 is Na, sodium.

atomic number 20 is ca, calcium.

Answer 2

Answer:

A - Sodium

B - Calcium

Sodium is highly reactive than calcium. In general in the entire periodic table the trend of reactivity is as follows.

The reactivity generally decreases as we move from left to right in the periodic table and increases across the group. So with in a group the one with higher atomoic number is generally highly reactive.

So generally alkali metals are highly reactive than alkaline earth metals ( so Na is more reactive than Ca)

Sodium reacts with HCl:

Sodium metal reacts with hydrochloric

acid to produce salt and hydrogen gas.

Sodium metal reacts with hydrochloric

acid which produces hydrogen gas and

sodium chloride.

2Na(s)+2HCl(aq)→2NaCl(aq)+H2(g)

The reactants are sodium metal and

hydrochloric acid.