Sally wants to find out the volume of water needed to fill her ice-cube tray. she can't find a measuring cup, but she does have a ruler, so she measures the length, width, and depth of one of the holes in centimeters. here is her calculation of the total volume. label each number as exact, or not exact.

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.