C1 Atomic Structure Flashcards

1
Q

What is everything made of? a_____

A

atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a compound?

A

Compounds are substances formed from 2 or more elements, the atoms of each are in fixed proportions throughout the compound and they’re held together by chemical bonds.

Two or more elements chemically bonded together in fixed proportions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an atom

A

THe smallest particle we can break a substance into

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a molecule?

A

more than one atom chemically bonded together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a mixture>

A

More than one substance (elements or compounds) present but not chemically bonded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In an atom the number of electrons is equal to the number of protons. True or false

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is the mass in an atom concentrated

A

THe nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name the 4 state symbols

A

s= solid
l= liquid
g= gas
aq= aqueous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

WHat is aqueous

A

WHen a solute is dissolved in a solvent of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain a method for paper chromatography

A

-A spot of the mixture (pen ink) is placed on the bottom of the chromatography paper
-The chromatography paper is placed in the solvent (water)
-Solvent (water) soaks up through the paper
-THe different dyes in the ink will have different solubilities
-The more soluble the dye is, the further it will move up the paper
-THe picture is called a chromatogram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why do you draw the start line of paper chromatography in pencil

A

PEncil marks are insoluble and won’t dissolve in the solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain why you would be able to collect a more concentrated sample of ethanol from a mixture of water and ethanol using fractional distillation than using simple distillation

A

In fractional distillation you separate the water and ethanol
-In simple distillation the water and ethanol are not separated.
-In simple they both end up in the condenser
-In fractional the water remains in the round bottom flask and the ethanol ends up in the condenser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the relative masses of:
-proton
-electron
-neutron

A

proton: 1
electron: 0
neutron: 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What was the plum pudding model and who came up with it

A

JJ Thomson put forward a model that showed the atom as a ball of positive charge with electrons (plums) stuck inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What experiment did Rutherford, Geiger and Marsden carry out?

A

Alpha particle scatterig experiments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How did Rutherford prove the plum pudding model wrong.

A

He fired positively charged alpha particles at an extremely thin sheet of gold. In the experiment they expected particles to pass straight through the sheet or be slightly deflected.
This was because it was thought that the positive charge of each atom was thought to be very spread out through the ‘pudding’ of the atom.
Most particles did go straight through, however more were deflected than expected.
A small number were deflected backwards so the plum pudding model couldn’t be correct.
THis is because some particles were deflected back by the nucleus but most went through the empty space of the atom.
He proved the existence of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What was Rutherford’s model

A

THe nuclear model.
He proposed that electrons must orbit the nucleus in a cloud and the nucleus contains dense positively charged protons. (no neutrons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is the total mass of products formed in a reaction equal to the total mass of reactants?

A

Law of conservation of mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What did Bohr discover

A

-There could be no dense cloud of electrons around the nucleus as Rutherford described as it would be attracted to the nucleus and cause the atom to collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What did Bohr propose

A

He proposed that electrons orbited the nucleus in fixed shells
-Each shell being a fixed distance from the nucleus
-His theory of atomic structure was supported by many experiments and helped many scientists’ observations of the time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

WHat experiments did Bohr do

A

Heated up atoms noticing that different atoms gave out different colours (amount of energy) as they cooled down.

22
Q

What did James Chadwick discover

A

Neutrons

23
Q

What did John Dalton describe atoms as

A

solid spheres. these spheres made up different elements

24
Q

What does the atomic number show

A

How many protons
How many electrons

25
Q

What does the mass number or relative atomic mass show

A

number of protons and neutrons

26
Q

How do you find the number of neutrons

A

no. neutrons = mass no. - atomic no.

27
Q

Work out the number of neutrons in Chlorine (35, 17)

A

18

35-17= 18

28
Q

Why do atoms have no charge

A

THey have equal numbers of protons and electrons.
THerefore the charges balance out

29
Q

What is an ion

A

An ion is a charged atom or group of atoms

30
Q

What happens when an atom loses electrons

A

It becomes a positively charged ion

31
Q

What happens when an atom gains electrons

A

It becomes negatively charged ion

32
Q

How do you determine whether an atom will lose or gain electrons?

A

Whether it requires more energy to lose or gain

33
Q

What happens when Lithium (3, 7) loses one electron

A

It forms a positive ion with 3 protons, 4 neutrons, 2 electrons

34
Q

What is an isotope

A

a different form of the same element with the same number of protons but different number of neutrons

35
Q

What is different about an isotope

A

-Same atomic number, different mass number
-Identical chemical properties but different physical properties

36
Q

Name the sub-atomic particles in the nucleus of an atom

A

protons and neutrons

37
Q

What does filtration separate

A

Insoluble solids from liquids

38
Q

Name an example of a situation where filtration could be used

A

Sand and water

39
Q

Name 2 methods for separating soluble solids from solutions

A

-evaporation
-crystallisation

40
Q

Describe a method for evaporation

A

-Pour solution into an evaporating dish
-Slowly heat the solution using a bunsen burner. The solvent will evaporate and the solution will get more concentrated.
-Eventually crystals will start to form
-Keep heating the evaporating dish until all you have left are dry crystals

41
Q

Describe a method for crystallisation

A

-Pour solution into an evaporatingdish and gently heat the solution
-Some solvent will evaporate and the solution will get more concentrated
-When some of the solvent has evaporated, or when you see crystals start to form (the point of crystallisation), remove the dish from the heat and leave the solution to cool
-The salt will start to form crystals as it becomes insoluble in the cold, highly concentrated solution
-Filter the crystals out of the solution and leave them in a warm place to dry
-You could use aa drying oven or a desiccator

42
Q

Describe a method to separate rock salt.

A

Rock salt is a mixture of salt and sand.
-Salt is soluble in water but sand isn’t.
1. Grind mixture so salt crystals are small
2. Put the mixture in water and stir. Salt will dissolve but sand won’t
3. Filter the mixture to collect the sand.
4. Evaporate the water from the salt so that it forms dry crystals

43
Q

When is distillation used?

A

Separating mixtures that contain liquids

44
Q

What is the difference in what simple and fractional distillation separate

A

SImple- separate solutions
fractional- mixture of liquids

45
Q

Describe a method for simple distillation

A

-Simple distillation is used when separating out a liquid from a solution
–The solution is heated. The part of the solution with the lowest boiling point evaporates first.
-The vapour is then collected, condenses and is collected
-The rest of the solution is left behind in the flask
-You can use simp. distillation to get pure water from sea water. The water evaporates and eventually just salt is left in the flask

46
Q

What is the problem with simple distillation

A

You can only separate things with very different boiling points

47
Q

Describe a method for fractional distillation

A

-A mixture of liquids. e.g crude oil
-Put mixture in a flask and stick a fractionating column on top, then heat it
-THe different liquids will all have different boiling points- so will evaporate at different temperatures
-The liquid with the lowest boiling point evaporates first. When the temp. on the thermometer matches the boiling point of this liquid, it will reach the top of the column
-Liquids with higher boiling points might also start to evaporate. But the column is cooler towards the top. So they will only get so far up before condensing back towards the flask
-When the first liquid has been collected, you raise the temperature until the next one reaches the top.

48
Q

An atom of nitrogen has an atomic number of 7 and a mass number of 14, give the number of electrons, protons, and neutrons

A

protons- 7
electrons- 7
neutrons- 7

49
Q

A substance consists of atoms which all have the same number of protons and electrons but different neutrons. Explain why this is an element

A

It’s the number of protons in an atom that determin what type of atom it is, so if all the atoms have the same number of protons then the subtance is an element

50
Q

An isotope of iron, Fe, has a mass number of 56, and an atomic number of 26, give the number of electrons protons and neutrons

A

electrons = protons = 26
neutrons = 56-26 = 30