Atomic structure

Question 1

what are the subatomic particles and their charges?

Answer 1

protons (+), neutrons (/), electrons (-)

Question 2

what are the relative masses of subatomic particles?

Answer 2

protons- 1, neutrons 1, electrons 1/2000 (very small)

Question 3

where are the subatomic particles found?

Answer 3

protons and neutrons in nucleus and electrons in shells which orbit

Question 4

what’s an ion?

Answer 4

when charges in an atom aren’t balanced, different number of protons and electrons

Question 5

what’s atomic mass? what’s atomic number?

Answer 5

1. No. of protons+ neutrons
2. No. of protons/electrons

Question 6

How do we know two elements are the same?

Answer 6

if they have the same number of protons

Question 7

what’s an isotope?

Answer 7

the different forms of an element, where the no. of protons is the same but the no. of neutrons if different

Question 8

how do we calculate the relative atomic mass?

Answer 8

sum of (isotope mass x isotope abundance) / sum of abundances

Question 9

what’s a molecule? what’s a compound?

Answer 9

A group of 2 or more atoms, chemically bonded
A group of 2 or more different atoms, chemically bonded

Question 10

Define mixture.

Answer 10

Two or more substances NOT chemically combined but together in the same space.

Question 11

Describe filtration.

Answer 11

Uses filter paper to separate insoluable solids and liquids.

Question 12

Describe evaporation + crystallization.

Answer 12

Separates solutions. Heat (water bath) causes solvent to evaporate, remaining solution gets more concentrated and crystals start to form

Question 13

How can mixtures be seperated?

Answer 13

Filtration,
crystallization, simple distillation, fractional distillation and
chromatography

Question 14

What is thermal decomposition?

Answer 14

When a substance breaks down due to heat.

Question 15

Describe simple distillation.

Answer 15

Separates out a liquid from a solution. Heat up solution, liquid with lower BP evaporates then condenses (water jacket).

Question 16

Who founded the plum pudding model?

Answer 16

J.J Thompson

Question 17

Describe the plum pudding model

Answer 17

Suggested that the atom is a ball of
positive charge with negative electrons embedded in it

Question 18

Who found the existence of neutrons.

Answer 18

James Chadwick

Question 19

Who conducted the gold foil experiment?

Answer 19

Rutherford

Question 20

Go through the gold foil experiment.

Answer 20

Fired alpha particles (much denser) at gold foil. Some rebounded, some passed through, some deflected. (Nuclear model)

Question 21

What did the results of the gold foil experiment conclude?

Answer 21

Some deflected, rebounded, and passed through. Nucleus in centre, mostly empty space.

Question 22

Who found out about the existence of electron shells.

Answer 22

Niels Bohr.

Question 23

Go through the history of the atom.

Answer 23

Solid spheres- John Dalton
Plum pudding- J.J. Thompson
Nuclear model- Rutherford
(Adp) Nuclear model- Bohr
(Adp+) (Shells)- Chadwick

Question 24

In what order was each subatomic particle found?

Answer 24

Electron, proton and neutron

Question 25

Why do atoms react?

Answer 25

To get an outer shell (gain/lose electrons) to be unreactive

Question 26

What is meant by an ‘unstable’ atom?

Answer 26

It wants to react with another atom to have a full outer shell

Question 27

In what order is the modern periodic table arranged?

Answer 27

Increasing atomic number —>

Question 28

What’s relative atomic mass?

Answer 28

An average value that
considers the abundance of the isotopes of the element

Question 29

Why is the periodic table arranged the way it is?

Answer 29

Increasing atomic number, so that elements with similar properties are in
columns, known as groups.

Question 30

What do the groups show in the periodic table?

Answer 30

Number of electrons in outer shells (similar properties)

Question 31

How were the early period tables arranged? Why was this not appropriate?

Answer 31

In order of atomic weights, some elements were
placed in inappropriate groups if the strict order of atomic weights
was followed.

Question 32

What did Mendeleev do to overcome the problems in the early periodic table?

Answer 32

He left gaps in the periodic table for elements he thought has not been discovered.

Question 33

When metals react, what do they form?

Answer 33

Positive ions.

Question 34

When non-metals react, what do they form?

Answer 34

Negative ions.

Question 35

Why do metals form positive ions when they react?

Answer 35

They have fewer electrons in their outer shell, so they lose electrons

Question 36

Why do non-metals form negative ions?

Answer 36

They have more electron in the out shell, so they need to gain electrons

Question 37

Why do metals get more reactive as you go down the table?

Answer 37

The atoms gets bigger so there are more shells. Electrons further away from nucleus so less force of attraction.

Question 38

What some of the differences between metals and non-metals.

Answer 38

Metals- Malleable, strong, conductors, shiny + sonorous
Non-metals- Brittle, Dull, low MP/BP, poor conductors