Apole vaulter runs forward, plants his pole, rises in the air and lands. what point represents his greatest amount of gravitational potential energy? a) when he initially lands b) as he runs forward to plant the pole c) just before he starts to fall to the ground eliminate d) after take-off as the pole expands and lifts the vaulter toward the bar

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.