Question

Answer this question please!!!!

Answer 1

Explanation:

Given -

• An element of 1st group and 3rd period of the periodic table, catches fire when exposed to air.

To Find -

1. Identify the element.
2. Write its atomic number and electronic configuration
3. Write a balanced chemical equation when it burns in air
4. what happens when the formed oxide is dissolved in water? write reaction.

As it is given that the atom belongs to group 1 and period 3.

It is cleared that, the atom is Sodium (Na).

Atomic number of sodium is 11.

Electronic configuration :-

1s² 2s² 2p^6 3s¹ or ¹⁰[Ne] 3s¹

When sodium burns in air it forms sodium oxide.

Chemical equation :-

4Na + O2 → 2Na2O

When sodium oxide is dissolved in water then it forms sodium hydroxide

Chemical equation :-

Na2O + H2O → 2NaOH