Module 3: Atomic Theory

Question 1

philosophers during the 5th century that said all matter was composed of small, finite particles, that they called atomos

Answer 1

Leucippus and Democritus

Question 2

meaning of atomos

Answer 2

indivisible

Question 3

philosopher that said matter is the “four elements” and could be infinitely divided; held sway over for over 2000 years

Answer 3

Aristotle

Question 4

he revolutionized chemistry with his hypothesis that the behavior of matter could be explained using an atomic theory

Answer 4

John Dalton

Question 5

when did John Dalton published his postulates about his atomic theory

Answer 5

1807

Question 6

also called the law of constant composition

Answer 6

Law of Definite Proportions

Question 7

This law states that all samples of a pure compound contain the same element in the same proportion

Answer 7

Law of Definite Proportions

Question 8

This law states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other elements in a ration of small, whole numbers

Answer 8

Law of Multiple Proportions

Question 9

This law states that 2 elements that form 2 different compounds will have different ratio of the elements

Answer 9

Law of Multiple Proportions

Question 10

the experiment of J. J. Thomson

Answer 10

Cathode Ray Experiments

Question 11

cathode ray particles are known as what now?

Answer 11

Electrons

Question 12

who discovered the charge to mass ratio of an electron

Answer 12

J.J. Thomson

Question 13

the experiment of Robert A. Millikan

Answer 13

Oil Drop Experiment

Question 14

In 1909, he was able to determine the charge of a single electron

Answer 14

Robert A. Millikan

Question 15

charge to mass ratio of an electron

Answer 15

1.759 x 10e11 C/kg

Question 16

charge of a single electron

Answer 16

1.5 x 10e-19

Question 17

In 1904, he proposed the “plum pudding” model which described a positively charged mass with an equal amount of negative charge in the form of electrons embedded in it

Answer 17

J.J. Thomson

Question 18

the experiment of Ernest Rutherford

Answer 18

Gold-foil experiment

Question 19

he performed a series of experiments using a beam of high-speed, positively charged alpha particles that were produced by radioactive decay of radium

Answer 19

Ernest Rutherford

Question 20

He discovered that the volume occupied by an atom consist of a large amount of empty space and the center is a small, heavy positively charged body

Answer 20

Ernest Rutherford

Question 21

He discovered electrons

Answer 21

J.J. Thomson

Question 22

He discovered protons

Answer 22

Ernest Rutherford

Question 23

He found evidences of neutrons in 1932, uncharged subatomic particles with mas approximately the same as that of protons

Answer 23

James Chadwick

Question 24

Theory that state that an atom contains a very small nucleus composed of protons and neutrons surrounded by a much larger volume of space containing electrons

Answer 24

Modern Atomic Theory

Question 25

the unit of mass that is used for masses of atoms, molecules, and subatomic particles

Answer 25

Atomic mass unit (amu)

Question 26

This is defined with regard to the most abundant isotope of carbon (Carbon-12)

Answer 26

Atomic mass unit (amu)

Question 27

1 amu is equivalent to how many grams?

Answer 27

1.6606 x e-24 g

Question 28

Does the fundamental unit of charge equals the charge of an electron?

Answer 28

yes

Question 29

Fundamental unit of charge of an electron

Answer 29

e = 1.602 x 10e-19

Question 30

The number of protons in the nucleus of an atom

Answer 30

Atomic Number (Z)

Question 31

Its value determine the identitiy of the atom

Answer 31

Atomic Number (Z)

Question 32

The total number of protons and neutrons

Answer 32

Mass Number (A)

Question 33

formula for number of neutrons

Answer 33

A - Z