Which element consists of positive ions immersed in a “sea” of mobile electrons? A.
Sulfur
B.
Nitrogen
C.
Calcium
D.
Chlorine

A positive ion is an atom or a molecule that has a net positive charge. The charge of the proton in an atom or a molecule is positive.

A subatomic found in the atom or the molecule that lacks a positive charge is called an electron.

The correct answer is:

Option C. Calcium

This can be explained by:

Calcium is the only metal found in the given list and hence is the answer.

To learn more about electrons, protons and metals follow the link:

link

Calcium

Explanation:

Calcium is the only metal here

hope this helps...

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.