What is true about the element calcium(ca, atomic number 20)? choose all that apply. it has 2 valence electrons it has 4 valence electrons it is a nonmetal it is a metal

It has 2 valence electrons

It is a metal.

Explanation:

Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal.

In chemistry, a metal is an element that readily forms positive ions (cations) by losing electrons.

Calcium belongs to group 2 and would give up it's two valence electrons in reactions.

The electronic configuration is given as;

Ca : 1s2 2s2 2p6 3s2 3p6 4s2 or [Ar] 4s²

Valence electron represents the outermost electrons.

The correct options are;

It has 2 valence electrons

It is a metal.

relative humidity is a measure of the amount of moisture in the air relative to the total amount of moisture the air can hold.

so d

a chemical reaction happens

explanation: