Calculate the amount of energy required to vaporize 287 grams of water at its boiling point. Hint: The heat of vaporization for water is 40.68 kJ/mol.

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.

the correct answer is a

just took the test and its a negative cl`

may be too late but may others : )