What do cells do when they are to closely packed together?

They will shut down.

Which of the following represents a negatively charged ion? of t 7

Plz quick a natural resource that is replaceable through a cycle in nature or sustainable practice is called a? the subject is science

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?