CFC, Freon, and aerosols are becoming less commonly used because they

A) cause acid rain.

B) harm the ozone layer.

C) have radioactive waste.

D) cause Alzheimer's disease.

Anything that has a mass and takes up space is? mixture, atom, gas, matter.

Supplies are dropped from an airplane on to a remote island. A parachute is used to reduce the impact when the supplies strike the ground.

What is the size of earth?

Which of these is an example of an abiotic part of the ecosystem? a. an invasive species b. a native species c. plant life d. weather

Edwin Hubble calculated the expansion rate of the universe. On what evidence did he base his calculation? /l "/l " A. Levels of background radiation /l "/l " B. Differences in redshift for galaxies /l "/l " C.

The force you exert on machine is called the?

22 What will NOT pollute the groundwater? F Motor oil spillage G Compost production H Injected radioactive waste J Lawn fertilizers

What is the oxidation state of a hydrogen atom bound to an iron atom.?

What evidence can you present for the possibility of time travel?

A ball is being rolled by a normal push of 1000N. it is opposed by friction which has a force of 0.3kN and air resistance which has a force of 23N. Calculate the resultant force.