Brainscape's Knowledge GenomeTM

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


See full index

IGCSE CHEMISTRY > Unit 2 -atomic Structure > Flashcards

Unit 2 -atomic Structure Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

Relative mass and charge of a proton

A 
Charge = +1
Mass = 1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Relative mass and charge of neutrons

A 
Charge = 0 or neutral 
Mass = 1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Relative mass and charge of electron

A 
Charge = -1
Mass = 0.0005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the atomic number of an element?

A

The number of protons in the nucleus (this is what defines an element).
Found at the bottom left of an element card

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

What is the mass number of an isotope/element

A

The total number of protons and neutrons in a nucleus.

Found top left of an element card

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

What is an isotope

A

The different forms of the same element that contain the same number of protons but different number of neutrons in the nucleus. They differ in relative atomic mass but not in chemical properties

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

What is the relative atomic mass

A

The relative atomic mass of an element (Ar) is an average value of mass for the isotopes of the element compared to 1/12 of carbon (RAM 12)

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

How to work out relative atomic mass of an element from the relative abundances of its isotopes

A

Add the percentages of each isotope.
Eg ISO1 = X mass, y% ISO2= A mass, B%

RAM = (X * Y/100) + (A * B/100)

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

What does an atom consist of ?

A

Atoms consist of a central nucleus, composed of protons (+1) and neutrons (+/-0), surrounded by electrons (-1) in orbiting shells

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

How many electrons can each shell hold ?

A 
Maximum of 2 X n²
ie. 
Shell 1 = 2 e
Shell 2 = 8 e
Shell 3 = 18 e
Shell 4 = 32 e
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Number of electrons in a neutral atom =

A

Number of protons

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

What is a cation

A

A positively charged ion
Has more protons than electrons
Cations are PUSSitive

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

What is an anion

A

A negatively charged ion.

Has more electrons than protons

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

How are ions formed

A

When a neutrally charged atom gains or loses electrons

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

What is ionic bonding

A

Bonding between a metal and a non metal.
The metals lose electrons and give them to the non metals so that they can become stable (8 electrons in the outer shell).
This bonding is strong electrostatic attraction between oppositely charged ions

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

What elements have stable electron arrangements (8 electrons in the outer shell)

A

Noble gasses

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

Can you predict the charge of an ion from ionic bonding?

A

Yes. See how many electrons it has in its outer shell and see how many it needs to gain/lose in order to have 8 electrons in its outer shell.

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

Do ionic compounds have high melting points?

A

Yes. Ionic compounds have high melting and boiling points because of the strong electrostatic attraction between oppositely charged ions.

19
Q

What is an ionic crystal

A

An ionic crystal is a three-dimensional lattice structure held together by attraction between oppositely charged ions

20
Q

What is electric currant

A

Electric current is the flow of electrons or ions

21
Q

In what state will ionic compounds conduct electricity

A

Ionic compounds will only conduct electricity when molten or in a solution

22
Q

Why do ionic compounds only conduct electricity when molten or in a solution

A

Because of the attraction between the anions and cations, the ions/electrons are not free to move in a solid state. However, when molten or dissolved, these ions are free to move

23
Q

What is a covalent bond

A

The sharing of a pair of electrons between two atoms in order to become stable.
Covalent bonding only happens in non-metals.
Covalent bonding is a strong attraction between the bonding pair of electrons and the nuclei of the atoms involved in the bond

24
Q

Do covalent compounds with simple molecular structures have high or low melting/boiling points

A

Covalent compounds have low melting/boiling points.
Even thought the covalent bonds are very strong, the molecules are held together by weak forces. Therefore, covalent compounds how low melting/boiling points

25
Q

What are substances with molecular structures

A

Solids, liquids, or gases with low melting points

26
Q

Do substances its giant covalent structures have high or low melting/boiling points

A

Giant covalent structures (giant lattice) have high melting/boiling points in terms of the breaking of so many strong covalent bonds

27
Q

Do covalent structures conduct electricity?

A

Covalent structures do not conduct electricity. This is because a covalent bond is formed between non metal atoms, which combine together by sharing electrons. Covalent compounds have no free electrons and no ions so they don’t conduct electricity.

28
Q

What is a metal

A

A giant structure of positive ions surrounded by a sea of delocalised electrons

29
Q

Why do metals conduct electricity so well

A

Because of the sea of delocalised electrons, the electrons can flow easily forming an electric currant

30
Q

Are metals malleable

A

Yes. Metals can be bent and shaped because they consist of layers of atoms that can slide over one another when the metal is bent, pressed, or hammered

31
Q

Why would you use a flame test

A

The colour of the flame can be used to identify the group 1 or 2 element present in a compound

32
Q

How do you conduct a flame test

A

Use a clean rod made of platinum or silicone glass
Dip rod in concentrated HCl and then then powdered substance
Put it in the blue Bunsen burner flame
Observe the colour of the flame

33
Q

What colour does the cation Li+ give in a flame test

A

Carmine red

34
Q

What colour does the cation Na+ give in a flame test

A

Intense yellow

35
Q

What colour does the cation K+ give in a flame test

A

Lilac

36
Q

What colour does the cation Ca++ give in a flame test

A

Brick red

37
Q

Properties of giant ionic lattices

A 
Hard, brittle crystalline substances 
High melting/boiling points
Soluble in water 
Insoluble in non-polar solvents 
Don't conduct electricity when solid but do when molten or dissolved in water
38
Q

Properties of covalent simple molecular lattices

A 
Soft solids
Low melting/boiling points 
Soluble in non-polar solvents but insoluble in water
Don't conduct electricity in any state
Made up of simple molecules
39
Q

Properties of giant covalent lattices

A

Hard (if 3D) or flakey (if 2D), crystalline solids
Very high melting points
Insoluble in most solvents
Do not conduct electricity in any state (except graphite)
Made up of atoms joined to each other by covalent bonds in an extended lattice

40
Q

Properties in giant metallic lattices

A

Hard
High melting/boiling points (not with alkali metals)
Malleable and ductile
Conduct heat and electricity both solid and molten
Soluble in liquid metals but not other solvents
Reactive metals do react with water

41
Q

What is an ionic equation

A

Only the ions which changed state. Charge and state are included (often colour too)

42
Q

What is a group in the periodic table

A

A verticals column of elements which all have the same number of electrons in their outer shell and have fairly similar properties

43
Q

What is a period in the periodic table

A

A horizontal row of elements which have the same number of occupied shells of electrons

IGCSE CHEMISTRY (16 decks)

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