What is the percentage increased in the volume of a gas when the pressure is reduced to half at constant temperature?

100% increase.

Explanation:

At constant temperature we have the relation

P1V1 = P2V2    where P and V are pressures and volumes, so here we have, say

P1 = 10, P2 = 1/2* 10 = 5  , V1 = 10 , V2 = ?

10 * 10 = 5 * V2

V2 = 100/5 = 20.

The original volume was 10  so the volume has doubled.

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.