Brainscape's Knowledge GenomeTM

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


See full index

GCSE CHEMISTRY > C1 > Flashcards

C1 Flashcards

1
Q

what does atoms contain?
what is the radius of an atom?

A

They contain:
-Protons
-Neutrons
-Electrons

Radius of an atom- 1x10-10 m/0.1 nanometers

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

where is nucleus located in the atom?
what does nucleus contain?
what is the radius of nucleus?
what is the charge of the nucleus and why?
where is the whole of the mass located?

A

-Its located in the middle

-protons and neutrons

-radius- 1X10-14m

-it has positive charge because of the protons

-concentrated in the nucleus

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

what does electrons do in the atom?
what are 5 facts about the electron?

A

-move around the nucleus in electron shells
5 facts:
-volume of their orbits determines the size of the atom
they have no mass
negatively charged and tiny /take a lot of space

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

why do atoms have no charge overall?
why do the charges cancel out?

A

-This is because they have the same number of protons as electrons

-They cancel out because electrons same size as the charge of a proton

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

what is an ion?
why does an ion have an overall charge?

A

-ion is an atom or a group of atoms that has lost or gained electrons

  • number of protons doesn’t equal to the number of electrons
    example- an ion with 2- charge has two more electrons than protons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does the atomic number tell you?
what does the mass number tell you?
how do you work out neutrons?

A
  • atomic number- how many protons/electrons

-mass number- total number of protons and neutrons

-To work out neutrons you subtract mass number and atomic number

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

what is an element?
what sub atomic particle decides the type of atom eg?

A
  • Element is a substance made up of atoms that all have the same number of protons in their nucleus

-Protons decide

example: atom has one proton in the nucleus its called hydrogen an atom that has 2 protons is called helium

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

how can atoms be represented and an example?

A

-Atoms can be represented by 1 or 2 letter symbol
example- c=carbon
mg=magnesium

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

what are isotopes?
what do isotopes have the same of and different of?

A

-Different forms of the same element which have the same number of protons but different number of neutrons

-Same atomic number but different mass numbers

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

how do you work out relative atomic mass?

A

sum of (Isotope abundance × isotope mass number)
DIVIDED BY
sum of abundance of all the isotopes

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

what happens when elements react?
what are compounds?

A

-when elements react atoms combine with other atoms to form compounds
-compounds are substances formed from two or more elements the atoms of each are in fixed proportions throughout the compounds and they’re held together by a chemical bond

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

what does making bonds do?
what is needed to separate original elements from a compound?

A

-Making bonds involves atoms giving away taking or sharing electrons. Only the electrons are involved the nuclei of the atoms aren’t affected at all when a bond is made
–A chemical reaction is needed because its difficult

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

what does compounds formed from non-metals and metals consist of?
which metals form positive ions and negative ions?
what is ionic bonding and examples

A

-Consist of ions
-Metal atoms lose electrons to form positive ions
-Non metals gain electrons to form negative ions
-Opposite charges of ions mean that there strongly attracted to each other eg magnesium oxide, calcium oxide and sodium chloride

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

what do compounds formed from non metals consists of?
what is covalent bonding?

A

-They consists of molecules
-Covalent bonding is each atom shares an electron with another atom eg hydrogen chloride gas, carbon monoxide

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

why is the properties of a compound totally different from the properties of the original elements?

A

TO explain:
TO explain:
Iron a ( lustrous magnetic metal and sulfur a (yellow powder) react compound formed (iron sulfide) is a dull grey solid dump and doesnt behave anything like iron or sulfur

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

what do physical separation techniques need?
what is filtration used to separate?
what does insoluble mean?
what is state symbols?

A

-They are needed to separate mixtures
-Filtration is used to separate an insoluble solid from a liquid
-Insoluble means the solid will not dissolve in liquid
-State symbols tell us the physical state of a chemical eg (I) or (s)

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

what are the 4 steps for filtration?
equipment?

A

USING A:
-filter tunnel
-filter paper
-conical flask
Eg-
AGCL(s)+H2O
silver chloride does not dissolve in water

1)We start by pouring our mixture into filter paper
2)The water passes through the tiny pores in the filter paper
3)The silver chloride cannot pass through the filter paper so it is trapped
4)At the end we have our liquid separated from our solid

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

what is crystallisation?
what is the example

A

-Crystallisation used to separate a soluble solid from a liquid
-Sodium chloride and water and sodium chloride is soluble in water
NaCl (aq)= dissolved in water

19
Q

what is the 4 steps for crystallisation?

A

1) Pour the solution into an evaporating dish and gently heat the solution.Some of the solvent will evaporate and the solution will get more concentrated
2)Once some of the solvent has evaporated or when you crystals forming remove the dish from the heat and leave the solution to cool
3) Salt should start to form crystals as it becomes insoluble in the cold,highly concentrated solution
4)Filter the crystals out of the solution and leave them in a warm place to dry

20
Q

what is simple distillation?
what are the 3 steps for it?
where else can you use simple distillation?
what is a problem with simple distillation?

A

-Simple distillation is used from separating out a liquid from a solution

1)Solution is heated the part of the solution that has the lowest boiling point evaporates first
2)The vapour is then cooled condenses (turns back into liquid) and is collected
3)The rest of the solution is left behind the flask

You can use simple distillation to get pure water from seawater.Water evaporates and is condensed and collected.Eventually you will just end up with salt in the flask
The problem is you can only use it to separate things with very different boiling points

21
Q

what is fractional distillation?
what are the 5 steps?

A

Fractional distillation is if you got a mixture of liquids

1)You put your mixture in a flask and stick a fractionating column at the top.Tenheat it
2)Different liquids will have different boiling points so they will evaporate at different temperatures
3)The liquid with the lowest boiling point evaporates first.When the temperature on the thermometer matches the boiling point of this liquid it will reach the top of the column.
5)Liquids with higher boiling points might also start to evaporate.But the column is cooler towards the top, so they will only get part of the way up before they start condensing and running back down towards the flask.
6)When the first liquid has been collected you raise the temperature until the next one reaches the top

22
Q

what did john dalton describe atoms as at the start of the 19th century?
what did jj thomson conclude from his experiments in 1897?
what was the new theory called?
what did it show?

A

-He described them as solid spheres and said that different spheres made up different elements
-JJ thomson concluded that atoms weren’t solid spheres.His measurement of charge and mass showed that an atom must contain even smaller negatively charged particles- electrons
-The new theory was called ‘plum pudding model’.Plum pudding model showed the atom as a ball of positive charge with electrons stuck in it

23
Q

what did ernest rutherford and his student conduct in 1909?

what did they expect in the plum pudding model?

what made the plum pudding not right?

what idea did rutherford discrover?

what happened when the alpha particles came near the concentrated positive charge of the nucleus?

A

-They conducted the famous alpha scattering experiments.They fired positively charged alpha particles at thin sheet of gold
-They expected the particles to pass straight through the sheet or be slightly deflected.This was becuase the positive charge of each atom was thought to be very spread out through the ‘pudding ‘ of the atom.
Most of the particles did go straight through the gold sheet and some were deflected and a small number were deflected backwards.SO it couldn’t be right
-Rutherford came up with an idea to explain this new evidence-nuclear model of the atom.In this there’s a tiny positively charged nucleus at the centre where most of the mass is concentrated.A ‘cloud’ of negative electrons surround this nucleus so most of the atom is empty space.
-When the alpha particle came near the concentrated positive charge of the nucleus they were deflected.If they were fired directly at the nuclues they were deflected backwards.

24
Q

what did niels bohr model explain?
what was his theory supported by?
what experiments did rutherford do to show the existence of protons?
what did james chadwick carry out?

A

-He explained that atom suggested that all the electrons were contained in shells.He said the electrons orbit the nucleus in fixed shells
-Bohr’s atomic theory of the atomic structure was supported by many experiments and it helped to explain lots of other scientist observations at the time.
-Further experiments by rutherford showed that the nuclues can divided into smaller particles.These were named protons.
-James chadwick carried out an experiment which provided evidence for neutral particles in the nucleus which is now called neutrons known as the nuclear model

25
Q

what do electrons always occupy?
what type of energy level is filled first?
when are atoms much happier?
what is in most atoms?
how do you work out the electronic configuration?

A

-Shells
-Lowest energy level is always filled first
1st shell=2
2nd shell=8
3rd shell=8
-Atoms are much happier when they have full electron shells-noble gases
-In most atoms outer shell is not full
EG
electric configuration for nitrogen
nitrogen atomic number is 7.This means it has 7 protons so it must have 7 electrons so it would be 2,5

26
Q

what are 2 obvious ways to categorise elements?
what did mendeleev do in 1869?
how were isotopes discovered?

A

-Their physical and chemical properties and their atomic weight

-Mendeleev put the elements mainly in order of atomic weight.Eg Te and I iodine actually has smaller atomic weight but is placed right after tellerium as it has similar properties
-Gaps were left in the table make sure that elements with similar properties stayed in the same groups.Some of these gaps meant undiscovered elements and allowed mendeleev to predict what their properites might be
-The discovery of isotopes in the early 20th century confirmed that mendeleev was correct to not place elements in a strict order of atomic weight but to also take account of their properties.Isotopes of the same element have different masses but have the same chemical properties

27
Q

in the periodic table what order are the elements laid out of and what does it mean?
what do elements with similar properties form?
what are the vertical columns called?
what does the group number tell you?
what happens if you know the properties of one element?
what is trend reactivity for group 1 and group 7?

A

-In order of increasing atomic (proton) number.Arranging the patterns like this meant that they are repeating patterns in the properties of the elements
-Elements with similar properties form columns
-Vertical columns are called groups
-Group number tells you how many electrons there are in the outer shell eg group 1 have one electrons in their outer and so does group 7 they 7 electrons
-If you know the properties of 1 element you can predict the other elements in that group.
-Group 1 - elements react more vigourously as you go down the group
-Group 7- reactivity decreases as you go down
-Rows are called periods.Each new periods represents another full shell of electrons

28
Q

what are metals?
what are non metals?

A

-Metals form positive ions when they meet.They are towards the bottom and to left of the periodic table
-Non metals are at the far right and the top of the periodic table.They don’t generally form positive ions when they react

29
Q

what do atoms react to form and how do they do this?
what do metals to left and bottom do?
what does both these effects mean?

A

-They react to form a full outer shell.They do this by losing gaining or sharing electrons
-Metal to the left of the periodic table don’t have many electrons to remove.
-Metals towards the bottom of the periodic table have outer electrons which are a long way from the nucleus so feel a weaker attactions
-Both these effects mean not much energy is needed to remove the electrons so it’s less feasible for elements to react and form positive ions

30
Q

why for non-metals is forming positive ions difficult?

A

-This is because its difficult because they have lots of electrons to remove to get a full outer shell.Outer electrons are close to the nucleus so feel strong attraction.It’s far more feasible for them to even share or gain electrons to get a full outer shell

31
Q

what does metals having metallic bonds mean?
why do non-metals not have metallic bonding?

A

-Metals have metallic bonding which causes them to have similar basic properties
-Theyre strong but can bent or hammared
-They are great at conducting heat and electricity
-They have high melting or boiling points
-Non-metals dont have metallic bonding because they don’t exhibit the same properties as metals.They tend to be dull looking more brittle dont conduct electricity lower density aren’t always solids at room temp

32
Q

what is group 1 metals and examples?
how many electrons do they have?
what are alkali metals like?

A

-Alkali metals like lithuim sodium potassium etc
-They have one electron in their outer shell which makes them very reactive and gives them similar properties
-Alkali metals are soft and have low density
-The trends for alkali metals
-increasing reactivity outer electron is more easily lost
-lower melting and boiling pointa
-Higher relative atomic mass

33
Q

why do group 1 elements don’t need much energy?

A

-This is becuase to lose their one outer electron to form a full outer shell they are readily form 1+ ions

33
Q

what happens when they are put in water group 1?
the more reactive an alkali metal is the more…?
what do they produce?
what do they form?

A

-They react vigorously
-The more reactive an alkali metal is the more violent the reaction
-They produce hydrogen the amount of energy given out when they react increases down the group
-They also form hydroxides that dissolve in water to give alkaline solutions

34
Q

what do group 1 metal react vigorously with when heated?

A

-In chlorine gas to form white salts called metal chlorides
-As you go down the group reactivity increases so the reaction with chlorine get more vigorous

35
Q

what do group 1 metal react with to form a metal oxide?
what do different type of oxide form depending on?

A

-Oxygen
-Different type of oxide will form depending on group 1 metals
–lithuim reacts to form lithuim oxide

36
Q

what are group 7 called?
what is fluorine?
what is chlorine,bromine and iodine?
what do they all exist as?

A

-Halogens
-Fluorine is a very reactive poisonous yellow gas
-Chlorine is a fairly reactive poisonous dense green grass
-Bromine is a dense poisonous red brown volatile liquid
-Iodine is a dark grey crystaline solid or a purple vapour
-They all exist as molecules which are pairs of atoms

37
Q

What happens as you go down group 7?
why do all group 7 react in similar ways?
what can halogen atoms share with to achieve a full outer shell?
what do compounds formed when halogen reacts all have?

A

-Become less reactive-harder to gain an extra electron
-Have higher melting and boiling points and relative atomic masses
-React in similar ways because they all have 7 electrons in their outer shell
-They can share electrons via covalent bonding with other non-metals to achieve a full outer shell
-The compounds that form when halogens react with non-metal all have simple molecular structures

38
Q

what do halogens form ion?
what are the compounds that form?
when can a displacement reaction occur between a halogen and…?

A
  • 1- ions called hallides when they bond with metals
    -The compounds that form have ionic structures
    -Displacement reaction can occur between a more reactive halogen and the salt of a less reactive one eg chlorine can displace bromine and iodine from aqeous solution of its salt
39
Q

what are group 0 elements called?
how many electrons do they have in their outer energy level?
what type of gases do they exist as?
what are all the elements of group 0 like?

A

-Noble gases like helium neon and argon
-They have 8 electrons in their outer eneergy level apart from helium who has 2.Helium don’t need to give up electrons or gain electrons to become more stable.
-They exist as monatomic gases single atoms not bonded to each other
-All elements in group 0 are colourless gases at room temp
-They are intert theyr’e non -flammable

40
Q

do the boiling points increase or decrease as they go down in noble gases?
why is the increase in boiling points?
what is the pattern for them?

A

-The boiling points of the noble gases increase as you move down along with increasing relative atomic mass
-Due to an increase in the number of electrons in each atom leading to greater intermolecular forces

helium
neon
argon
kyrpton GOING DOWN
xenon
radon

41
Q

what is another method to separate salt from a solution?
what are the 3 steps of evaporation?
what are the 4 steps for crystallisation and filtration used to separate rock salt?

A

-Evaportation
1)Pour solution in a evaporating dish
2)Gently heat the solution.The solvent will evaporate and the solution will get more concentrated.Eventually crystals will start to form
3)Keep heating the evaporating dish until you are left with dry crystals

Rock salt is simply a mixture of salt and sand. Salt and sand are both compounds but salt dissolves in water and sand doesn’t

1)Grind the mixture to make sure the salt crystals are small so will dissolve
2)Put the mixture in water and stir.Salt will dissolve but sand won’t
3)Filter the mixture.The grains of sand won’t fit through the tiny holes in the filter paper so they collect on the paper instead.The salt passes through the filter paper as it part of the solution
4)Evaporate the water from the salt so that it forms dry crystals

42
Q

what can the parts of a mixture either be?
whats in a compound that a mixture doesn’t have?
what are the properties of a mixture? eg

A

-Parts of a mixture can be either elements so they can be separated
-There no chemical bond between different parts of a mixture
-The properties of a mixture are just a mixture of the properties of the separate parts - chemical properties of a substance aren’t affected by it being part of a mixture eg mixture of iron powder and sulfur powder will show the properties of both iron and sulfur.It will contain.It will contain grey magnetic bits of iron and bright yellow bits of sulfur

43
Q

what are the 10 steps of paper chromatography?

A

1)Draw a line near the bottom of a sheet of filter paper (USE A PENCIL BECAUSE THEY ARE INSOLUBLE WONT DISSOLVE IN THE SOLVENT)
2) Add a spot of the ink to the line and place the sheet in a beaker of solvent
3)The solvent used depends on what’s being tested.
4)Make sure the ink isn’t touching the solvent
5)Place a lid on top of the container to stop the solvent evaporating
6)The solvent seeps up the paper carrying the ink with it
7)Each different dye in the ink move up the paper at a different rate so the dye will separate out.Each dye will form a spot in a different place
8)If any of the dyes in the ink are insoluble in the solvent you used they will stay on the baseline
9)When the solvent has nearly reached the top of the paper take the paper out of the beaker and leave it to dry
`10)The end result is a pattern of spots called a chromatogram

GCSE CHEMISTRY (9 decks)

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