The amount of matter in an object is its Mass...
I believe the answer is C because the first two are mechanical hazards and C mentions plug which is electrical.
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between at