Student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are:
liquid a: the solid dissolves quickly.
liquid b: the solid appears unchanged.
liquid c: a brownish colored liquid is produced.
liquid d: fizzing occurs and the well becomes warmer.
in which well does a physical change occur?

sure im new too!

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.