Covalent is when atoms actually are with each other

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

hope this !

a lot of people sadly don't know the best way to learn is cheating off of your friends or this amazing thing called google

answer;

-chlorine

explanation;

-toxic industrial chemicals are industrial chemicals that are manufactured, stored, transported, and used throughout the world. toxic industrial chemicals can be in the gas, liquid, or solid state.

-they can be chemical hazards (e.g., carcinogens, reproductive hazards, corrosives, or agents that affect the lungs or blood) or physical hazards (e.g., flammable, combustible, explosive, or reactive).