Chem 3.1 and 3.2 The Atomic Theory

Question 0

Law of Indefinite Proportions

Answer 0

A compound has the same ratio by mass of each element

Question 1

Water is always what percent oxygen and hydrogen

Answer 1

90% O

10% H

Question 2

Law of Multiple Proportions

Answer 2

The same two elements may form more than one compound

Question 3

Dalton’s Atomic Theory

Answer 3

Atoms are the smallest indivisible particles of matter
A chemical reactions is only a rearrangement of atoms
Atoms of the same element are identical to each other
Atoms of different elements are different from each other (different masses)
Atoms combine in whole number ratios to create compounds

Question 4

Which of Daltons theory are not entirely true

Answer 4

Atoms are the smallest, indivisible particles of matter

Atoms of the same element are identical to each other

Question 5

What did JJ Thompson use to determine the existence of electrons

Answer 5

Charged plates in 1897

Question 6

What type of model did Thomson make for the atom in 1900

Answer 6

Plum pudding, electrons embedded through atoms, evenly distributed mass and positive charge throughout atom.

Question 7

Why did Thomson believe electrons were negatively charged

Answer 7

They were attracted to positive plates

Question 8

Why did Thomson believe electrons were subatomic

Answer 8

They were 2000x lighter that the lightest atom

Question 9

Which of Dalton’s atomic theory became untrue after Thomson’s existence of electron

Answer 9

Atoms are the smallest indivisible particle of matter

Question 10

In Thomson’s model where is the mass located

Answer 10

Throughout the atom

Question 11

Where is the positive charge in the Thomson model

Answer 11

The overall shape aside from electrons

Question 12

How did Thomson know there must be a positive charge

Answer 12

To balance the positive charge

Question 13

Alpha particles

Answer 13

Positively charged radioactive particles

Question 14

What were the components of Rutherfords experiment

Answer 14

Alpha particles, nm thick gold foil, fluorescent screen

Question 15

According to Rutherford, what are 2 characteristics about the atomic nucleus in order for the alpha particle to be deflected

Answer 15

Positive charge
Small
Holds 99.99% of atoms mass

Question 16

What subatomic particles did the alpha particles deflect off of during Ritherfords experiment

Answer 16

Protons, because they have the same charge