Atomic Str

Question 1

What are atoms perceived as?

Answer 1

Minute fuzzy spheres with a dense central structure

Question 2

Who proposed the Four Elements theory?

Answer 2

Ancient Greeks

Question 3

What is an element?

Answer 3

A substance that cannot be split into a simpler substance by chemical means

Question 4

What are atoms defined as?

Answer 4

Tiny indivisible, indestructible particles unique to each element

Question 5

What happens when atoms combine to form compounds?

Answer 5

They do so in fixed whole number ratios

Question 6

Who discovered cathode rays?

Answer 6

William Crookes

Question 7

What did Crookes call the negative particles?

Answer 7

Electrons

Question 8

What did John Dalton contribute to atomic theory?

Answer 8

Matter is made up of atoms that can neither be created nor destroyed

Question 9

What does the term ‘cathode rays’ refer to?

Answer 9

Radiation that passes from the cathode to the anode in a vacuum tube

Question 10

Fill in the blank: An atom is made up of _______ particles.

Answer 10

Indivisible

Question 11

True or False: Atoms can be created and destroyed.

Answer 11

False

Question 12

What did scientists conclude about the structure of atoms?

Answer 12

They are composed of unique particles called atoms

Question 13

How did Crookes demonstrate the existence of cathode rays?

Answer 13

Using a paddle wheel that moved towards the anode

Question 14

Who suggested a name for negative particles?

Answer 14

William Crookes

Question 15

What are the four elements according to the ancient Greeks?

Answer 15

Earth, air, water, and fire

Question 16

What is the significance of the term ‘fixed whole number ratios’?

Answer 16

It describes how atoms combine to form compounds

Question 17

What does the term ‘matter’ refer to?

Answer 17

Substances composed of atoms

Question 18

Fill in the blank: The movement of cathode rays can be observed using a _______.

Answer 18

Paddle wheel

Question 20

Who is J.J. Thomson?

Answer 20

A physicist who showed that cathode rays were negatively charged particles and calculated the ratio of the size of charge of electrons to mass.

Question 21

What model did J.J. Thomson propose?

Answer 21

The Electron and Plum Pudding Model.

Question 22

What did Rutherford show about the atom?

Answer 22

That the atom is mostly space with a dense nucleus.

Question 23

What did Rutherford discover about protons?

Answer 23

He bombarded atomic nuclei and pushed out positive particles which he called protons.

Question 24

What experimental setup did Rutherford use to explore atomic structure?

Answer 24

He bombarded thin gold leaf foil with alpha particles.

Question 25

What was observed when alpha particles were bombarded on gold foil?

Answer 25

Most alpha particles passed straight through, while some were deflected at large angles.

Question 26

What is the atomic number of gold?

Answer 26

79+.

Question 27

Fill in the blank: J.J. Thomson calculated the ratio of the size of charge of electrons to _______.

Answer 27

[mass].

Question 28

True or False: Most alpha particles were only slightly deflected when bombarded on gold foil.

Answer 28

True.

Question 29

What happens to a few alpha particles during Rutherford's experiment?

Answer 29

They were repelled back.

Question 30

What charge did the metal plate have in the context of the cathode ray experiment?

Answer 30

Negatively charged.

Question 31

What type of particles did Rutherford refer to as positive particles?

Answer 31

Protons.

Question 32

What did the bombardment of the atom's nuclei by Rutherford eventually lead to?

Answer 32

Release of protons and positively charged particles.