P1.1 the particle model

Question 1

Describe JJ Thompson’s plum pudding model

Answer 1

• Discovered electrons
• Positive mass sphere=plum pudding
• negative electrons=Plums

Question 2

Describe Rutherford’s experiment

Answer 2

• Gold foil experiment
• fired positive alpha particles at thin gold foil
• most went through-most of atom is vacuum
• some deflected-shows nucleus is positive
• some repelled-shows the nucleus has smol volume

Question 3

Describe Rutherford’s nuclear model (MY ALBATROSS NEEDS MONEY)

Answer 3

• Mass concentrated at the center in the nucleus
• All the positive charge in the nucleus
• negative electrons orbit the nucleus in shells
• Most of the space is a vacuum

Question 4

Why models change over time

Answer 4

• Understanding

* oldermodels can’t explain new evidence

Question 5

Neutron

Answer 5

• Mass 1
• charge 0
• Found in nucleus

Question 6

proton

Answer 6

• Mass 1
• charge 1+
• found in nucleus

Question 7

Electron

Answer 7

Mass 0.0005

charge -1

found in electron shells

Question 8

Size of an atom

Answer 8

1×10-10m

Question 9

Density equation

Answer 9

Density (kg/m3)=mass (kg) / volume (m3)

• P=m/V

Question 10

Describe how to find the mass of a regular solid

Answer 10

Find themassusing anelectronic balance
mesure thelength of each side using a ruler 📏
Find the volume (length × width× height)
density=mass/volume

Question 11

How to find volume

Answer 11

Volume= length× width× height

Question 12

How to find density of an irregular solid (method 1)

Answer 12

Find the mass using an electronic balance.

Half fill a measuring cylinder with water and note the

volume.

Put the object in the water.

The difference in the volumes is the volume of the object.

density = mass / volume

Question 13

How to find the density of an irregular solid (method 2)

Answer 13

Find the mass using an electronic balance.

Fill a displacement can with water.

Put the object in the water and collect the water that

comes out in a measuring cylinder.

The volume of the water is the volume of the object.

density = mass / volume

Question 14

How to find density of a liquid

Answer 14

Find the mass of a measuring cylinder using an electronic
balance.

• Put the liquid in a measuring cylinder and note the volume
  Find the mass of a measuring cylinder and liquid using an
  electronic balance.
  Subtract the two masses to find the mass of the liquid on
  its own.
  density = mass of liquid / volume of liquid

Question 15

Properties of a solid

Answer 15

• Fixed pattern arrangement
• packed close together
• strong forces of attraction
• vibrate
• Hard to compress
• Fixed volume
• high density

Question 16

Properties of a liquid

Answer 16

• Packed and touching
• less close together
• some force of attraction
• move on top and around each other
• hard to compresss
• takes shape of bottom of container
• fixed volume
• can flow
• medium density

Question 17

Properties of a gas

Answer 17

• randomly arranged
• spread far appart
• almost 0 force between particles
• move free and fast
• Easy to compress
• takes shape of entire container
• fills volume of container
• can flow
• low density

Question 18

List the changes of state

Answer 18

• S to L =melting
• L to G = boiling
• G to L= condensing
• L to S = freezing

Question 19

What is sublimation

Answer 19

Go straight from a solid to a gas