What element is in group 2 and period 3 of the periodic table

pure water does not conduct electricity very well. however, when certain substances are dissolved in water, the solution does conduct electricity. you can make a simple device that shows how well a solution conducts electricity. this device uses a flashlight bulb to indicate how well the solution conducts electricity. the better the solution conducts electricity, the brighter the bulb will glow.

explanation:

a:

by the combination of an unlimited number of elements

it means there are 3 atoms of oxygen