Filtration, decantation, and evaporation are examples of

ways in which scientists distinguish between elements and compounds
separation by chemical means
separation by physical means
ways in which scientists separate compounds

What pressure will be exerted by 0.675 moles of a gas at 25*c if it is in a 0.750-l container?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.