Chapter 2 - Atomic Structure

Question 1

Law of conservation of mass.

Answer 1

Matter is neither created nor destroyed in the course of a chemical reaction.

Question 2

Who made the atomic theory and what was it?

Answer 2

Dalton.
All matter is made up of atoms, all atoms are indivisible, the atoms of a given element are all identical.

Question 3

Who discovered cathode rays?

Answer 3

Crookes.

Question 4

Describe the experiment to find cathode rays.

Answer 4

The Maltese cross.
Cathode rays produce a flouresce and travel in straight lines (produce a shadow).
Travel from the negative terminal of the battery towards the positive.

Question 5

Describe oil drop experiment.

Answer 5

Voltage applied to a fine mist of electrically charged oil drops, causing an upward electrical force to act on the drops. Voltage adjusted until it balances gravitational force, and they are suspended mid-air to measure charge.

Question 6

Result of paddle wheel experiment.

Answer 6

Cathode rays have enough energy to cause the paddle wheel to move towards the positive terminal.

Question 7

Who disproved plum pudding?

Answer 7

Rutherford.

Question 8

Describe the gold foil experiment.

Answer 8

Rutherford bombarded a thin gold foil of alpha particles. Zinc sulfide screen to detect particles.

Question 9

What particles did rutherford find.

Answer 9

Nucleus and proton.

Question 10

How did Rutherford discover protons?

Answer 10

Bombarded 6 elements with alpha particles, all gave out same positively charged particle. Concluded that hydrogen nuclei produced in breakup of nuclei of bombarded atoms. Called them protons but couldn’t explain mass.

Question 11

How were neutrons discovered?

Answer 11

Chadwick bombarded beryllium with alpha particles with a paraffin wax block behind the apparatus, a neutral charged particle was hitting it.