A cold front forms when A.
cold air rises and creates a vacuum.

B.
cold air moves under warm air and pushes the warm air upwards.

C.
warm air collides with cold air, but neither has enough energy to move above or below the other.

D.
warm air moves in below existing cold air and pushes the cold air upwards.

What is limiting reactant? with examples

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure