Plz help asap Choose all the answers that apply.

The elements in group 18 .

are highly reactive
are gases at room temperature
usually do not react with other elements
are in a group called the noble gases
are nonmetals

What must occur for air masses to form fronts

Amixture with the same composition throughout is!

Asubstance is held in an open container. its particles move past one another at random speeds but do not leave the container. heat is removed from the system, and the particles slow down. when enough heat is removed, the particles no longer have enough speed to overcome the weak attractive forces between them. when this happens, the substance enters its solid state. the process described above is known as .