Which describes the letter that belongs where the question mark is?

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions

Movement that is like a t a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. transfers energy from one location to another a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave