Kinetic/ particle theory (C15)

Question 1

kinetic theory is based on what ideas?

Answer 1

-All substances are made up of particles (atoms, ions and molecules).
-The particles are attracted to each other, some strongly and others weakly.
-The particles move around (have kinetic energy).
-The kinetic energy of the particles increases with temperature.

Question 2

Explain melting?

Answer 2

With continued heating, the particles eventually have sufficient energy to overcome some of the attractive forces holding them in their fixed positions, and they slide past one another. he temperature at which this occurs is the melting point of the substance (at a given pressure).

Question 3

Does temperature rise (even with continued heating) during melting?

Answer 3

no, once all the substance has melted (become a liquid), the temperature of the liquid will rise.

Question 4

what is evaporation?

Answer 4

Some particles on the surface of the liquid can, through collisions, have enough energy to completely overcome the attractive forces holding them in the liquid and they escape into the gas (vapour) state