An oxygen tank is at 20C contains 28 moles of energy and the gauge reads 31 atm. After two weeks the gauge reads 10.5 . How much oxygen was used during the two week period

idk

explanation:

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.