I need help solving the picture

Explanation:

These problems are pretty easy, you just need to do to the enthalpy what is done to the equation itself. Numbers one and 3 are reversed, so they become positive values. When a coefficient changes in the equation, you multiply the enthalpy by that number. I have attached my work below. Let me know if there is any confusion left.

Hope this helped! :^)

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.