The valency of both Oxygen and magnesium is 2 why

One significant difference between an ionic bond, where electrons are taken from one atom and added to another atom, and a covalent or metallic bond, where electrons are shared is

Aspirin has a density of 1.40 g/cm3 what is the volume in cubic centimeters of a tablet weighing 320 mg ?

Determine the ph of 0.10 m nh3 solution. nh3 is a weak base with a kb equal to 1.8 x 10-5 round answer to nearest whole number.