Matter and Particles

Question 1

What is the equation that defines density?

Answer 1

Density = Mass / Volume

Question 2

What is the unit of mass?

Answer 2

Kilogram

Question 3

What is the unit of volume?

Answer 3

m^3

Question 4

What is the unit of density?

Answer 4

kg/m^3

Question 5

What are the three observations of the Geiger-Marsden experiment?

Answer 5

Most particles pass straight through the gold foil.Some particles are deflected by small angles.Very few particles are backscattered.

Question 6

What are the consequences of the Geiger-Marsden experiment?

Answer 6

The nucleus is mostly empty space.The nucleus is positively charged.The nucleus is small and dense.

Question 7

What observation in the Geiger-Marsden experiment implies that the nucleus is mostly empty space?

Answer 7

Most particles pass straight through the gold foil.

Question 8

What observation in the Geiger-Marsden experiment implies that the nucleus is positively charged?

Answer 8

Some particles are deflected by small angles.

Question 9

What observation in the Geiger-Marsden experiment implies that the nucleus is small and dense?

Answer 9

Very few of the particles are backscattered.

Question 10

What is the implication of the observation that most particles pass straight through the gold foil in the Geiger-Marsden experiment?

Answer 10

The nucleus is mostly empty space.

Question 11

What is the implication of the observation that some particles are deflected by small angles in the Geiger-Marsden experiment?

Answer 11

The nucleus is positively charged.

Question 12

What is the implication of the observation that very few particles are backscattered in the Geiger-Marsden experiment?

Answer 12

The nucleus is small and dense.

Question 13

Describe Rutherford’s Nuclear Model.

Answer 13

A small, dense positive nucleus surrounding by a cloud of negative electrons. Mostly empty space.

Question 14

What is the name of the model of the atom that was developed in the wake of the Geiger-Marsden experiment?

Answer 14

Rutherford’s nuclear model.

Question 15

Describe the particles in a solid.

Answer 15

Strong bonds, vibrating around fixed positions, slow speeds, small distances between them.

Question 16

Describe the particles in a liquid.

Answer 16

Weak bonds, free to move around within the confines of the liquid, moderate speeds, moderate distances between them.

Question 17

Describe the particles in a gas.

Answer 17

Very weak/non-existant bonds, free to move around the container, fast speeds, large distances between them.

Question 18

What is the phase transition from a solid to a liquid?

Answer 18

Melting

Question 19

What is the phase transition from a gas to a liquid?

Answer 19

Condensation

Question 20

What is the phase transition from a liquid to a gas?

Answer 20

Boiling

Question 21

What is the phase transition from a liquid to a solid?

Answer 21

Freezing

Question 22

What charge does a proton have?

Answer 22

+1

Question 23

What charge does an electron have?

Answer 23

-1

Question 24

What charge does a neutron have?

Answer 24

0

Question 25

What is the mass number of an atom?

Answer 25

The number of protons plus the number of neutrons in the nucleus.

Question 26

What particles are in the nucleus of an atom?

Answer 26

Protons and neutrons

Question 27

What is the proton number of an atom?

Answer 27

The number of protons in the nucleus.

Question 28

What is an isotope?

Answer 28

An atom that has the same number of protons, but different numbers of neutrons.

Question 29

Describe the motion of particles in a gas.

Answer 29

Rapid and random

Question 30

What is temperature?

Answer 30

A measure of the average kinetic energy of an object.

Question 31

How does Brownian motion provide evidence that the motion of gas/liquid particles is random?

Answer 31

Larger particles (e.g. pollen) suspending in a sea of smaller particles (e.g. water) appear to "jitter" and move randomly...... this occurs due to collisions of large number of smaller particles with the larger particle......which suggests that, as the motion of the large particle is random, the motion of the smaller particles are random.

Question 32

What happens to the average speed of particles as I increase the temperature?

Answer 32

Increases

Question 33

In a fixed container, what happens to the pressure of a gas when I increase temperature?

Answer 33

Increases

Question 34

Explain how gases exert pressure.

Answer 34

The particles have kinetic energy and move around. The particles collide with the walls and change direction. In doing so, they exerted a force on the wall. When you add up all these forces and divide by the area, because P=F/A you get a pressure.

Question 35

Explain, in terms of particles, why increasing temperature increases the pressure?

Answer 35

The particles move faster which means they collide more often with the wall and they collide harder with the wall, which means the force is greater. P=F/A, so if you increase the force, you increase the pressure.