1)why we use dilute acid in the preparation of H2 gas 2)why don't use HNO2, rather than use HCl and H2SO4 in the H2 gas preparation.​

the correct answer is option d

explanation:

i was wrong its d because they dont use cm when calculating square roots

your parents i think this could be it

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.