If element X has an atomic mass of 32 amu, and element Z has an atomic mass of 118 amu, and element U has an atomic mass of 2 amu, what is the
percent by mass of Z in the following?
ZU3X

the answer is 75.0%.

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.