Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry > C2a > Flashcards

C2a Flashcards

1
Q

What is the atomic number?

A

The number of protons / electrons

Bottom number

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

What is the mass number?

A

Top number

No of protons and neutrons

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

Mass of protons, neutrons and electron

A

P- 1
N-1
E- 1/2000

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

What is a compound?

A

Formed when atoms of two or more elements are chemically combined together.

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

What is an isotope?

A

Different atomic forms of the same element, which have the same number of protons but different number of neutrons.

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

What is ionic bonding?

A

atoms loose or gain electrons to form ions (charged particles)

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

How does ionic bonding work?

A

If an atom has 1 electron in its outer shell or only needs 1 to be complete ionic bonding is conducted as they want to be the same as a nobel gas. The two atoms latch onto each other and gain/loose electrons.

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

Properties of an ionic compound?

A

Always have giant ionic lattices
Closely packed regular lattice arrangement
Strong electrostatic forces of attraction
High melting and boiling points as lots of energy is needed to break the electrostatic forces.
dissolve easily as ions can separate to carry electric current

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

If an element gains/looses an electron what charge to they get?

A

Gain - negative

Loose - positive

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

What is an ion

A

Atoms that have lost or gained an electron

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

What happens is a negative and positive ion react with each other?

A

The two balance each other out.

eg Na+ and Cl- become NaCl

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

How do you draw diagrams of two atoms that are ions or have been ionically bonded?

A 
You have to move the electron in the outer shell and then put brackets around each atom with the charge in the corner
_              _
|                  |  + or -
|                  |
|                  |
|_              _|
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is covalent bonding?

A

When atoms share electrons in their outer shell to get full outer shells and be like nobel gases

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

How is methane covalently bonded?

A

1 carbon and 4 hydrogen

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

How is ammonia covalently bonded?

A

1 nitrogen and 3 hydrogen

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

Properties of a simple molecular substance

A

Strong covalent bonds to form small molecules
Weak intermolecular forces
Low melting and boiling point
Dont conduct electricity as they are ions so no electric charge
Gases and liquid at room temp
E.g oxygen, water, chlorine

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

Properties of giant covalent structures

A 
No charged ions
Strong covalent bonds
High boiling and melting points
Dont conduct electricity
e.g Diamond, graphite and silica
18
Q

Properties of a diamond

A 
rigid
each carbon had 4 covalent bonds
shape of a pyramid 
No charged ions
Strong covalent bonds
High boiling and melting points
Dont conduct electricity
19
Q

Properties of graphite

A 
each carbon has 3 covalent bonds
in layers so can slide over each other
soft and slippery
No charged ions
Strong covalent bonds
High boiling and melting points
weak intermolecular forces
20
Q

Properties of metals

A

Giant structure
strong forces of electrostatic attraction
Bent and shaped easy
Conduct electricity/heat

21
Q

Why can a metal conduct electrify

A

Have free electrons

The delocalised electrons come from outer shell and are free to move which carries heat and electricity through metal

22
Q

Why can metals be bent and shaped easily?

A

There atoms are in layers meaning that they can slide over each other easily

23
Q

What is an alloy?

A

Mix of two or more metals

24
Q

Why are alloys harder than pure metals?

A

They have different sized atoms which distort the atoms layers so they can’t slide over each other easily making them harder.

25
Q

Example of a smart material

A

Shape memory alloy
alloy made from nickel and titanium
You can bend and twist it but it will always return to its original shape.
Used in glasses and braces

26
Q

What is a nanoparticle?

A

A very small particle which is around 1-100 nanometers across.

27
Q

What is nano science?

A

The science of very small particles and develop new uses for them

28
Q

Properties and uses of nanoparticles?

A

Very strong
huge surface area compared to volume - so used as catalysts
Used in cosmetics like suncreams so they don’t leave white on skin
Conduct electricity - so used for small electric circuits.

29
Q

What is the difference between thermosetting and thermosoftening polymers

A

Thermosoftening - don’t have cross-linking chains so they are easy to melt. They can be remoulded as many times as you like. Weak intermolecular forces

Thermosetting - Strong intermolecular forces between crosslinks that hold chains firmly together so are very solid structures that are strong, hard and rigid.

30
Q

How is low density polythene made?

A

Heating ethene at about 200 degrees under high pressure - is flexible and used for bags and bottles

31
Q

How is high density polythene made?

A

heating ethene - Lower temperature and pressure with a catalyst. - more rigid and used in water tanks and drainpipes.

32
Q

What is relative atomic mass?

A

Ar
The mass number of an element
Basically how heavy it is
compared to carbon-12

33
Q

What is relative formula mass?

A

Mr

The relative atomic mass of each individual component of the compound, added together.

34
Q

What is a mole?

A

The relative formula mass (Ar / Mr) of a substance in grams is known as one mole of that substance

35
Q

How do you work out the number of moles?

A

Number of moles = Mass in g (of
element/compound
—————————————–
Mr (of element/compound)

36
Q

How do you calculate percentage mass of an element in a compound?

A

Ar x No of atoms (of that element)
————————————————– x 100
Mr (of whole compound)

37
Q

How do you find the empirical formula?

A
  1. List all the elements in the compound
  2. Underneath write how much is being used of that element in the experiment
  3. Divide this number by the Ar of that element
  4. Turn the numbers into nice whole numbers by timing by 10
    5, Divide the 2 numbers so they are in the simplest form
38
Q

How do you calculate mass in a reaction?

A
  1. Write out the balanced equation
  2. Work out the Mr for the things involved in question
  3. Then divide the 2 numbers to find 1g of the substance
  4. Times that number by the number asked for in the question.
39
Q

How do you work out percentage yield?

A 
Actual yield (grams)
------------------------------       x 100
Predicted yield (grams)
40
Q

Why do you never get 100% yield?

A

Reaction is reversible
Lost throughout the experiment
Sometimes unexpected reaction take place that use reactants.

41
Q

How can you separate artificial colours?

A

Paper chromatography

When you put ink/dye on filer paper then put into into a solvent (water) This will force colours to separate.

42
Q

How does gas chromatography work?

A

A gas is carried through a column that is packed with a solid material. The substances travel through at different speeds causing them to sepertate.

Chemistry (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions