A student draws a model of an atom to help him determine how the atom will interact with other atoms. Why is the model helpful? The model is easier to see than an actual atom.
The model accurately represents all properties of the atom.
The model behaves in the same way as an actual atom.
The model shows the properties of the atom that the student needs to know.

answer: your mm

explanation:

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.