Crystal meth refers to a. methamphetamine crystals, which may be smoked. b. the "high" experience after injecting methamphetamine. c. methamphetamine imported from Colombia. d. methamphetamine capsules

Option A.

Explanation:

Crystal meth is a type of methamphetamine drug that is in form of glass or shiny bluish rocks. It is a highly addictive stimulants that affect the Central nervous system. It is used to treat sleep disorder and attention deficit hyperactivity disorder. The drug increases the dopamine level in the brain. Dopamine is a natural chemical that is involved in body movement, motivation and behaviors. It can be use by smoking or swallowing or snorting.

compost can be added to topsoil as a:

pesticide

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.