Atomic Theory And Models

Question 1

What is the Plum Pudding model?

Answer 1

Atoms are made mostly out of positively charged material, like dough in a bun. The negatively charged electrons are found inside the positive dough

Question 2

Who created the Plum Pudding model?

Answer 2

JJ Thomson

Question 3

When did Thomson’s introduce his theory?

Answer 3

1897

Question 4

What did Democritus contribute to the atomic theory?

Answer 4

He said:

Matter is formed of small pieces that could not be cut into smaller parts called atomos meaning uncuttable

Question 5

When did Democritus introduce his theory?

Answer 5

430 BC

Question 6

What information did John Dalton contribute to the atomic theory?

Answer 6

1) Atoms are tiny,invisible particles
2) Atoms of one element are all the same
3) Atoms of different elements are different
4) Compounds form by combining atoms

Question 7

When did John Dalton introduce his theory?

Answer 7

1808

Question 8

The positively charged particle in an atom

Answer 8

Proton

Question 9

What is a proton?

Answer 9

The positively charged particles in the nucleus

Question 10

Atom model

Answer 10

A representation of an Atom (a picture of what the atomic theories explain)

Question 11

Atom

Answer 11

The smallest particle in which an element can be divided and still be the same substance

Question 12

John Dalton

Answer 12

British Chemist who developed his atomic theory gathered from observations gathered during his experiment.

Question 13

Electron

Answer 13

The negatively charged particles in an atom that are involved in the formation of chemical bonds

Question 14

Particle

Answer 14

A tiny piece or part

Question 15

Nucleus

Answer 15

The tiny extremely dense positively charged region in the center of an atom, made of protons and neutrons

Question 16

Bohr Model

Answer 16

The model of the atom that states that electrons move around the center of the atom’s nucleus in fixed orbit; also called the planetary model

Question 17

Ernest Rutherford

Answer 17

Scientist Who stated that the atom was mostly empty space in at the center was a small dense positively charged nucleus

Question 18

Neils Bohr

Answer 18

Danish Scientist who suggested that electrons travel around the nucleus in fixed paths

Question 19

Fixed orbit

Answer 19

To revolve around an object in a fixed path

Question 20

Neutron

Answer 20

The particles of the nucleus that have no charge

Question 21

Quarks

Answer 21

The subatomic particles that make up protons, electrons, and neutrons.

Question 22

Subatomic particle

Answer 22

Any particles that are smaller than an atom

Question 23

Electron cloud

Answer 23

The regions inside an atom where electrons are likely to be found

Question 24

Mass number

Answer 24

The sum of the protons and neutrons in an atom

Question 25

John Thomson

Answer 25

British chemist whose experiments with the cathode-ray tube led to the discovery of electrons

Question 26

Atomic mass unit (amu)

Answer 26

The SI unit used to express the masses of particles in an atom

Question 27

Atomic number

Answer 27

The number of protons in the nucleus of an atom

Question 28

Atomic mass

Answer 28

The weighted average masses of all the naturally occurring isotopes of an element

Question 29

Chemical symbol

Answer 29

A shorthand way to write the name of an element

Question 30

Isotope

Answer 30

Atoms with the same number of protons but hav different numbers of neutrons

Question 31

Periodic table

Answer 31

A table of elements in order by increasing atomic mass

Question 32

Energy level

Answer 32

A region of an atom in which electrons if the same energy are likely to be found

Question 33

Why do scientists use models?

Answer 33

To help explain the structure of an atom

Question 34

What things makes an atomic model useful?

Answer 34

It must support all the information that is known about matter and the behavior of atoms

Question 35

_________'s model was a simple sphere

Answer 35

John Dalton's

Question 36

________ join with other _______ to form new substances

Answer 36

Atoms;atoms

Question 37

Who discovered the electron?

Answer 37

John Thomson

Question 38

When was Ernest Rutherford's atomic theory proposed?

Answer 38

1911

Question 39

Who discovered the nucleus of an atom

Answer 39

Rutherford

Question 40

Who said hat electrons travel in fixed orbits?

Answer 40

Neils Bohr

Question 41

What is Niels Bohr's model called?

Answer 41

Bohr model / planetary model

Question 42

What is the model we currently follow today?

Answer 42

Electron Cloud Model / Quantum Mechanics model

Question 43

What's the difference between the electron cloud model and Bohr's model?

Answer 43

Bohr's model showed electrons traveling in fixed paths, electron cloud had electrons scattered throughout randomly with no predicted pattern

Question 44

When did James Chadwick discover the neutron?

Answer 44

1932

Question 45

In 1932, _______ _______________ discovered the neutron in the center of an atom

Answer 45

James Chadwick

Question 46

Where are the electrons located in an atom?

Answer 46

The electron cloud

Question 47

What is atomic mass?

Answer 47

The weighted average masses of all the naturally occurring isotopes of an element

Question 48

What charge does a proton have?

Answer 48

Positive

Question 49

What charge does a neutron have?

Answer 49

Neutral / no charge

Question 50

What charge does an electron have?

Answer 50

Negative

Question 51

What was JJ Thomson's model of the atom called?

Answer 51

The Plum Pudding Model

Question 52

How many neutrons does a titanium atom have if: The atomic number is 22 The atomic mass is 48

Answer 52

26

Question 53

Which subatomic particles have the most mass?

Answer 53

Protons and neutrons

Question 54

Where are the protons and neutrons located?

Answer 54

The nucleus

Question 55

Why does and atom have a neutral charge?

Answer 55

Because a normal atom has the same amount of protons as electrons which cancel each other out

Question 56

How are the numbers of protons determined in an element

Answer 56

The atomic number

Question 57

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

Answer 57

You subtract the atomic number from the atomic mass

Question 58

What's the weakest force in the atom?

Answer 58

Gravity

Question 59

What is the strongest force in an atom?

Answer 59

Strong force

Question 60

What are the four forces in an atom?

Answer 60

1) Gravity 2) Electromagnetic Force 3) Strong Force 4) Weak Force

Question 61

Organize the forces in an atom from strongest to weakest

Answer 61

1) Strong Force 2) Electromagnetic Force 3) Weak Force 4) Gravity