Atomic Structure

Question 1

Who created the nuclear model of the atom and what qualities does it have? What model number was it ?

Answer 1

Rutherford 3

Positive nucleus *
Negatively charged Electrons dotted around inside the atom
Empty space*

Question 2

Who created the Plum Pudding model and what qualities does it have? What model number is it?

Answer 2

JJ Thompson 2

Negatively charged electrons dotted around *
Ball of positive charge *
Hard sphere

Question 3

Who created the Electron Shell Model and what qualities does it have? What model number is it?

Answer 3

Bohr 4

Electron shell *
Positive nucleus
Electrons have a negative charge
Empty Space

Question 4

Who created today’s model and the atom and what qualities does it have? What model number is it?

Answer 4

Chadwick 5

Protons and neutrons inside a nucleus *
Electron shells
Negative electrons on the shells
Empty Space

Question 5

Who created the first model and the atom and what qualities does it have?

Answer 5

Dalton

Hard sphere
Can’t be broken down into pieces
No charges

Question 6

What is an element? Give 3 examples

Answer 6

A pure substance that is only made up of one type of atom . They cannot be broken down into another substance . They can exist as single atoms or as molecules.

Oxygen, carbon, iron

Question 7

What is a compound? Give 3 examples

Answer 7

A substance that is made up of two or more DIFFERENT elements that are chemically bonded together. They cannot be separated without a chemical reaction.

Water, carbon dioxide, sodium chloride

Question 8

What is a molecule? Give 3 examples

Answer 8

Non-metal atoms that are chemically bonded together. They can be made from the same or from different atoms.

Water, oxygen, hydrogen

Question 9

What is a mixture? Give 3 examples

Answer 9

Two or more elements or compounds that ARE NOT chemically bonded together. They can be easily separated.

Air, sand and water, salt water

Question 10

What does the mass number of an element on the period table tell us?

Answer 10

The number of protons/electrons + the number of neutrons in an atom

Question 11

What does the atomic number of an element on the periodic table tell us?

Answer 11

The number of protons also the number of electrons in an atom

Question 12

What is an isotope?

Answer 12

Atoms of the same element, with different numbers of neutrons. (They have the same number of protons and electrons).

Question 13

What is relative atomic mass?

Answer 13

The average mass of the known isotopes of the element. It allows for relative mass and relative amount of that element.

Question 14

What is an ion?

Answer 14

An atom that has either gained or lost electrons

Question 15

How many electrons can each electron shell hold and how do you write how many are in each shell in short form?

Answer 15

The first can hold 2 after that additional shells can hold a maximum of 8
You write (#,#)
Always fill the inside shells first

Question 16

What is the link between the group number and the electron configuration?

Answer 16

The group number = the number of electrons in the last electron shell

Question 17

What is the link between the period number and electron configuration?

Answer 17

The period number = the number of electron shells

Question 18

What is conservation of mass?

Answer 18

Conservation of mass is that mass is neither created nor destroyed in chemical reactions,
Atoms at the start of the reaction = atoms at the end of the reaction just in a different arrangement

Question 19

What is the law of conservation of mass?

Answer 19

Mass reactants = mass products

Question 20

What do the endings -ate and -ide tell us?

Answer 20

-ide tells us the compound is made up of just two elements

-ate tells us there are three elements present and the third element is oxygen

Question 21

How do you balance an equation?

Answer 21

You add a ‘big’ number in front of the formula this will multiply the munchers of each atom/molecule.

Question 22

Name 4 separation techniques

Answer 22

Filtration, chromatography, distillation, evaporation

Question 23

How can you separate a mixture?

Answer 23

Using physical processes such as filtration, crystallisation, simple distillation and chromatography. These physical processes do not involve a chemical reaction.

Question 24

What are the definitions of solute, solvent and solution

Answer 24

Solvent = solid that is dissolved

Solvent = the substance that dissolves the solute

Solution = when the solute has dissolved in the solvent

Question 25

Ions always have a charge

When do they have a positive charge?

Answer 25

If an atom has lost electrons to form an ion.

Question 26

Ions always have a charge

When do they have a negative charge?

Answer 26

If an atom has gained electrons to form an ion.

Question 27

What are the relative charges of

A proton
A neutron
An electron

Answer 27

Proton : +1
Neutron : 0
Electron : -1

Question 28

What’s the relative mass of :

A proton
A neutron
An electron

Answer 28

Proton : 1
Neutron : 1
Electron : almost 0 or 1/2000

Question 29

What is the equation to calculate relative atomic mass?

Answer 29

Sum of (isotope abundance x isotope mass number)
______________________________________________________
Sum of abundances of all the isotopes (100)

Question 30

How do you work out relative atomic mass?

Answer 30

1. Multiply the mass of each isotope by its relative abundance
2. Add those together
3. Divide by the sum of the relative abundance

Example :

Element |Relative mass of isotope | Abundance (%)
—————————————————————————-
Chlorine | 35 | 75%
| 37 | 25%

R.A.M = (35 x 75) + ( 37 x 25)
_____________________ =35.5
75+25

Question 31

Why do atoms contain equal amounts of protons and neutrons?

Answer 31

The negative charge of the electrons cancels out the positive charge of the protons and therefore the charge is zero and the atom is neutral.

Question 32

How do you work out the rf in chromatography

Answer 32

RF = distance travelled by sample
—————————————
Distance travelled by solvent

Question 33

What is the rule on electron shells for group 0 elements

Answer 33

The last electron shell is always full