History Of The Atom

Question 0

Ernest Rutherford

Answer 0

The Nuclear Model

Question 1

John Dalton

Answer 1

The Billiard Ball Model

Question 2

Schrodinger

Answer 2

The Wave Mechanical Model

Question 3

JJ Thompson

Answer 3

The Plum Pudding Model / The Currant Bun Model

Question 4

Neils Bohr

Answer 4

The Planetary Model

Question 5

Difference: JJ Thompson & Ernest Rutherford (2)

Answer 5

Thompson - Positive sphere with negatives imbedded
- Mass is due to the electrons
Rutherford - Negative sphere with positives imbedded
- Mass is due to the nucleus (99,9%)

Question 6

The Billiard Ball Model Discoveries: (4)

Answer 6

• Matter consists of tiny particles called atoms. Can’t be broken up.
• Element have the same kind of atoms, mass and behavior.
• Atoms combine to form compounds in a fixed ratio
• A chemical reaction takes place when there is a rearrangement of the atoms.

Question 7

Difference = Ernest Rutherford & Neil’s Bohr (1)

Answer 7

Rutherford - Said nothing about the movements of the electrons.

Bohr - Said electrons orbited around in energy levels depending on the amount of energy it contained.

Question 8

The Plum Pudding Model = Discoveries (3)

Answer 8

• Negative sphere with positives imbedded in it.
• The atom was electrically neutral
• The mass of the atom was due to the electrons

Question 9

Neil’s Bohr & Schrodinger = Difference (1)

Answer 9

Bohr - Electrons orbit in fixed paths around the nucleus depending on their amount of energy.

Schrodinger - Electrons travelled in orbitals and looked like clouds.

Question 10

The Nuclear Model = Discoveries (4)

Answer 10

• Negative sphere with positives imbedded.
• 99,9% of mass is due to the nucleus.
• Nucleus is positively charged.
• The rest of the volume is due to the circling electrons.

Question 11

In Rutherfords experiment with the gold foil. State the observations and interpretations. (3x3)

Answer 11

O - Most alpha particles moved through undefeated.
I - An atom is made up of mainly empty space.

O - Some particles were deflected by a small angle.
I - The nucleus was tiny and had to be positively charged, so was the alpha particle.

O - Occasionally, the alpha particles travelled back from the foil.
I - The nucleus carries most of the atoms mass.

Question 12

Explain Rutherfords Expiriment: (3)

Answer 12

He beamed alpha particles at a piece of thin gold foil and detected the scintillations on a screen.

Question 13

What is an Alpha particle? (4)

Answer 13

- It has protons and neutrons.
  (He nuclei = 2 protons, 2 neutrons)
- It is very heavy
- It is positively charged
- Unstable

Question 14

What is a Beta particle? (3)

Answer 14

• Light
• Negatively charged
• Electron

Question 15

Ernest Rutherford

What is Radioactivity? (1)

Answer 15

• The giving off of particles.

Question 16

Heavy nuclei= (2)

Answer 16

• Unstable
• Decays (spontaneous split. Emits stray particles)
  = Radioactive

Question 17

How thick was the gold foil in Rutherford’s experiment? (1)

Answer 17

0,00004cm thick

A few 100 atoms thick

Question 18

JJ Thompson beamed what kind of rays and what charge were they? (1+2)

Answer 18

• Cathode Rays
• Negatively Charged
• Electrically Charged

Question 19

Explain Thompson’s Expirement? (5)

Answer 19

• Parallel metal plates connected to a battery
• In glass Tube
• Filled with glass
• As gas pressure decreased = gas began to glow
• Placing magnets above and below tube = DEFLECTION happened.

Question 20

Who created the neutron and 3 properties? (1+3)

Answer 20

= James Chadwick

• Same mass as proton
• Neutral
• Found in the nucleus

Question 21

What is an energy level? (1)

Answer 21

Region of space where an electron has fixed energy.

Question 22

Neil’s Bohr Time

What was the law of physics? (2)

Answer 22

• Electrons give off light

- Collapsing atom as a result

Question 23

Frequency (1)

Answer 23

• Number of vibrations per second.

Question 24

Why is blue light faster than red? (2)

Answer 24

• Vibrates faster

- Therefore more energy

Question 25

How to colour travel in Air and Solid Transparents? (2)

Give 2 examples of Solid Transparents (2)

Answer 25

• Air = same speed
• Solid Transparents = Different speeds
• Glass and Water

Question 26

Why does red light travel faster than blue in glass? (2)

Answer 26

• Glass causes blue light to bend more when it travels through a
• Denser medium

Question 27

White light through a prism creates? (1)

Answer 27

• A continuous spectrum (all 7 colors)

Question 28

Line spectrum is when what happens? (3)

Answer 28

• Electrons are in an excited state
• Release energy (quantum jump)
• To return to ground state
• This gives off light
  = The line spectrum

Question 29

Quantum Energy? (1)

Answer 29

• Difference in energy from one energy level to another

Question 30

What is the formula for the max. number of electrons? (2)

Answer 30

• 2n^2

Question 31

What is Ground state, Quantum jump and Excited state? (3)

Answer 31

• electrons at lowest energy state
• Jumping from one energy level to another
• When electron gains energy

Question 32

Electromagnetic spectrum? (1)

Answer 32

• The Balmer Series

Question 33

Ultra-Violet Spectrum? (1)

Answer 33

• The Lyman Series

Question 34

What is so fascinating about line spectrums? (1)

Answer 34

• Every element has a different atomic emission spectrum.

- Like a fingerprint

Question 35

Schrodinger replaced Bohrs energy level orbits with? (1)

Answer 35

• “clouds” “orbitals”

Question 36

Probability of the orbitals is shown as what and where does it go? (2)

Answer 36

• Lobes

- Extends from the nucleus in 3 dimensions

Question 37

What is an orbital? (2)

Answer 37

• An orbital is a three dimensional region around the nucleus where there is a high probability of finding an electron with a certain amount of energy.