Which chemical element with atomic number is 31?

Gallium

The correct answer is option 2. Gallium.

The chemical element with atomic number 31 is gallium.

1. Symbol: Ga

2. Atomic Number: 31

3. Category: Metal (post-transition metal)

4. Properties:

Gallium is a soft, silvery metal.

It has a melting point just above room temperature, around 29.76 degrees Celsius (85.57 degrees Fahrenheit), which allows it to melt when held in one's hand.

It has properties that are intermediate between aluminum and indium, the elements adjacent to it in the periodic table.

Gallium is not found in pure form in nature but is often extracted as a byproduct of aluminum and zinc production.