The method of determining the age based on measuring radioactive elements is called 1 Law of Superposition
2 Absolute dating
3 Approximate dating
4 Relative dating​

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).

i don't have a definite answer, but i would assume not based on my experiences with my friend when we both were taking a spanish course; however, it would probably still be to your benefit to look at what questions she received, just in case. a language course and a science course differ greatly, after all.