50.0 mL of 2.5 M barium nitrate reacts with 25.0 mL of 1.5 M calcium phosphate, how many grams of precipitate are created?

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

a electronegativity decreases beacuse the size of nucleus is bigger.

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.