Chapter 1 St: Atoms

Question 1

What is an Atom?

Answer 1

It is the smallest particle of matter. It cannot be chemically divided.

Question 2

Why have scientists devised various models to represent atoms?

Answer 2

Because atoms are too small to be examined directly.

Question 3

What is Dalton’s “Billiard Ball” model?

Answer 3

He discovered that atoms are the smallest solid units of matter and that atoms are solid and divisible.

Question 4

What is J.J Thompson’s model?

Answer 4

He suggested the “Plum Pudding” model of the atom and that negative charges distributed in a positive sphere.

Question 5

Why did Thompson show when referring to the “rays”? What did this indicate? What did he add?

Answer 5

He showed that the rays could be bent by nearby electric charges. This indicated that they were tiny negatively charges particles. He called them electrons. Thompson adds negatively charged electrons as part of an atom.

Question 6

What did Ernest Rutherford bombard?

Answer 6

He bombarded a thin Au foil with alpha particles (positively charged)

Question 7

Describe Rutherford’s “ray” results and conclusions.

Answer 7

1- result: went straight through. Conclusion: means atom is mostly empty space.
2- result: 1/1000 was deflected. Conclusion: means nucleus was positive and that the nucleus is very small.
3- result: 1/100 000 bounced back. Conclusion: means that nucleus is approximately 100 000 times smaller than the atom and the nucleus is very dense.

Question 8

Describe the Bohr Rutherford Atomic model

Answer 8

Proposed that electrons moved in energy levels and that the ones in the outermost orbit determined the chemical properties of that atom

Question 9

What does the Bohr Rutherford model contain (2)

Answer 9

Small positive nucleus (protons)
Surrounded by negatively charged electrons that move in defined orbits

Question 10

What did James Chadwick add?

Answer 10

Adds the neutron in nucleus

Question 11

Describe what a neutron is

Answer 11

One of the particles that make up an atom. With the proton, it forms the nucleus. It has no charge and is neutral.

Question 12

What is an electron

Answer 12

One of the particles that make up an atom and it is negatively charged

Question 13

What is a proton

Answer 13

One of the particles that make up an atom. It is found in the nucleus and carries a positive change.

Question 14

What is the symbol for the electron, proton, and neutron?

Answer 14

Electron = e-
Proton = p+
Neutron = n0

Question 15

Describe the simplified atomic model

Answer 15

Protons and neutrons in nucleus
Surrounded by a number of electrons in each energy shell.

Question 16

Finish the sentences.
Number of protons=
Number of electrons=

Answer 16

Atomic number
Number of protons.

Question 17

How does one find the # of neutrons?

Answer 17

Atomic mass-Atomic number= # of neutrons

Question 18

Where is the atomic mass located?

Answer 18

Underneath the element

Question 19

Where is the atomic number located?

Answer 19

On top of the element

Question 20

Describe the Energy Level: Octet Rule

Answer 20

For the first 20 elements, the orbitals are 2-8-8-18

Question 21

What must happen to orbits

Answer 21

They must be filled before starting a new one

Question 22

What are valence electrons?

Answer 22

They are the electrons in the outer most shell of an atom.

Question 23

What is the Lewis dot representation?

Answer 23

It is a simplified representation that shows the symbol of the element and only illustrates the valence electrons.

Question 24

What is a group?

Answer 24

-A column of the periodic table.
-elements in a group have similar chemical properties as they have the same amount of valence electrons.

Question 25

Give an example of a group

Answer 25

Group three all have three valence electrons.

Question 26

What is a period?

Answer 26

-A row of the periodic table.
-all elements in a period have the same amount of electron orbit/shells

Question 27

Give an example of a period

Answer 27

Each element in Period three has three shells/orbits

Question 28

What is a periodic table?

Answer 28

Classifies all elements according to certain properties.
Visual representation of the elements in groups according to their physical and chemical properties.

Question 29

How are the metals and non metals separated ?

Answer 29

By the staircase on the right side of the periodic table

Question 30

Describe metals

Answer 30

-good conductors for electricity and heat
-ductile and malleable
-usually shiny
-solid at room temperature (except for mercury)
-many react with acids

Question 31

Describe non metals

Answer 31

-poor conductors for electricity and heat
-many are gases at room temp
-when solid, they can easily be reduced into powder

Question 32

Describe metalloids

Answer 32

-properties depend on conditions
-can have properties of both metal and non metal (shiny, malleable, etc)

Question 33

What are Alkali Metals?

Answer 33

Soft and highly reactive metals.

In pure state: must be stored in oil.

Do not exist in their elemental state in nature.

Question 34

What are Alkaline Metals?

Answer 34

They are highly malleable and reactive metals

Burn easily

Can be exposed to air

Form many compounds found in rocks

Do not exist in their elemental state in nature.

Question 35

What are the names of Columns 3,4,5,6?

Answer 35

-boron
-carbon
-nitrogen
-oxygen

Question 36

What are Halogens?

Answer 36

They are non metals

Many are powerful disinfectants

React easily to form compounds, including salts

Question 37

What happens when Alkali Metals are stored in water

Answer 37

They burst into flames

Question 38

What are Noble or Inert Gases?

Answer 38

They are non metals

Very stable gases

React minimally with other elements

They almost always exist in their elemental state in nature.

Question 39

What is the Ball and Stick model?

Answer 39

It is where each element is connected with balls and sticks

Question 40

Do an example of ball and stick chemical equation

Answer 40

H—H H—H + O—O =
H—O—H + H—O—H

Question 41

What are the group names of 1.2,7,8?

Answer 41

1: alkali metals
2: alkaline metals
3: halogens
4: noble or inert gases

Question 42

Cathod ray theory;

Answer 42

-if they were attracted to the + plate, then they were negatively charged
-if they were easily deflected, they were light
-if they made a wheel turn, they had mass