Experiments and Structure of the atom in symbol form

Question 1

What are the 3 types of radiation?

Answer 1

Alpha
Beta
Gamma

Question 2

Alpha particles are _______ time heavier than electrons and twice the charge of an electron. They were also found to travel at ________ the speed of light coming from a radium source.

Answer 2

8000

On tenth

Question 3

Rutherford used alpha particles from ______ source to probe into atoms. His assistants arranged the apparatus to allow the alpha particles to pass through a slit in an evacuated glass tube and then onto a very thin _____ foil, about _____ atoms thick. They then used a telescope with a fluorescent screen on the end to view the scintillations produced by alpha particles striking the screen.

Answer 3

Radium
Gold
200

Question 4

• Because only very few alpha particles went straight through, he realized there had to be a very small ______ in the atom.
• Because alpha particles were moving at great speed and are about ______the mass of a gold atom he realized that most of the _____of the gold atom had to be in this very small nucleus.
• Because alpha particles were positively charged and were sometimes deflected through large angles he realized that the nucleus had to be highly ________charged.

Answer 4

Nucleus
1/50th
Mass
Positively

Question 5

Proton - Relative Mass/Relative Charge

Answer 5

1

+1

Question 6

Neutron-Relative Mass/Relative Charge

Answer 6

1

0

Question 7

Electron-Relative Mass/Relative Charge

Answer 7

1/2000

-1

Question 8

What is the mass number?

Answer 8

Also called the nucleon number and it is the number of protons and number of neutrons.

Question 9

What is the atomic number?

Answer 9

The proton number.

Question 10

How do you determine the number of neutrons in nucleus of an atom?

Answer 10

Subtract the atomic number from the mass number

Question 11

When analyzing the structure of an atom using symbolic notation remember that the larger of the two values represents _______ number while the smaller value represents the ________ number.

Answer 11

Mass

Atomic

Question 12

What are isotopes?

Answer 12

Atoms of the same element with different mass numbers.

Question 13

The difference in mass numbers is because they have different numbers of ________.

Answer 13

Neutrons

Question 14

Describe the model proposed by Thomson.

Answer 14

A positive sphere of charge with negative charges on the surface of the sphere.

Question 15

What is the relative mass,charge and penetrating ability of the types of radiation:(9)

Answer 15

Alpha=4amu,+2,low
Beta=1/2000 amu, -1, medium
Gamma=n/a,0,high