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59 Cards in this Set
- Front
- Back
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What are atoms? |
the smallest particle of a chemical element that can exist |
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What did John Dalton say atoms were? |
He described atoms as solid spheres and said that the spheres were made up of different elements |
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What did J J Thomson's findings show and what was it called? |
Plum pudding model- The charge and mass of an atom showed that the atom must contain smaller particles which were electrons. The new particle model looked like the one on the picture. |
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Who proved the plum pudding model wrong, how did he do this? |
Ernest Rutherford (1909) showed that the plum pudding model was wrong. Rutherford, Geiger and Marsden conducted the famous gold foil experiment which proved the plum pudding model wrong. |
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What is the gold foil experiment and who was it conducted by? |
The experiment was conducted by Rutherford, Geiger and Marsden. They fired positively charged particles at an extremely thin sheet of gold. The idea was that the particle should just bounce back but instead it mostly passed straight through with very few particles bouncing back. |
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What idea did Rutherford come up with after he conducted the experiment? |
He came up with the idea that the tiny positively charge nucleus is surrounded by a 'cloud' of negative electrons |
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What did the Bohr model show? |
Bohr model showed electrons in a shell, in a fixed orbit with fixed energy surrounding a nucleus. |
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What is the nucleus of an atom? |
-It is in the centre of the atom -It contains protons and neutrons -It has a positive charge because of the protons |
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What are the electrons of an atom? |
-Move around the nucleus in shells -They are tiny -They have virtually no mass |
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What is the mass and charge of a: -Proton -Neutron -Electron |
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Where is the mass number placed and where is the atomic number place on an atomic symbol of an element? |
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How do you work out the number of protons, neutrons and electrons from the atomic number and mass number? |
Protons=Atomic number Neutrons= Mass number - Atomic number Elecrtons= Atomic number |
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What do the groups and periods in a periodic table represent? |
Group- Number of electrons on the last outer shell Period- Number of shells in the atom |
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What are isotopes? |
Isotopes are different forms of the same elements, they have the same number of electrons and protons but a different number of neutrons |
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What did Döbereiner try to do? |
He tried to make the elements into triads, he put them with other elements with the same chemical property and usually the middle element of each had the same relative atomic mass that was the average of the other two. |
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What are elements? |
Elements are substances which are only made up of one element. |
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What did Newland do? |
Newland notices that every 8th element had similar properties so he listed the known elements in rows of seven, unfortunately the transition metals messed it up. |
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Why was Newland criticise? |
Newland was criticized because: - the groups contained elements with different properties -he mixed up non metals and metals -he did not leave any gaps for undiscovered elements. |
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What did Dmitri Mendeleev do? |
He created his table of elements with spaces so that his current elements could stay in the correct groups, when new elements were discovered they fit into the previously left spaces. |
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What are the rules of electron shells? |
1st shell= 2 electrons 2nd shell=8 electrons 3rd shell=8 electrons etc. |
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What is an Ion? |
An ion is an atom or molecule which has lost or gained electrons to become a charged molecule |
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What is an ionic bond? |
An ionic bond is when an atom loses or gain an electron to get a full outer shell. |
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If you lose an electron your charge is? If you gain an electron your charge is? |
Lose an electron = positive charge Gain an electron = Negative charge |
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What do ionic compounds form? |
Ionic compounds form a giant lattice structure which is closely packed together, the electrons are not free moving so electricity cannot flow through, as well s this they have very strong chemical bonds. |
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What does a material have to have before it can conduct electricity? |
The material has to have free moving ions. |
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How do metals and non-metals become ions? |
Metals lose electrons to become ions therefore become positively charged Non-metals gain electrons to become ions therefore become negatively charged |
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What is a covalent bond? |
Covalent bonding is when electrons are shared e.g. H2 or Cl2 The outer shell still has to be full of electrons for this to work |
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Describe a simple molecular substance. |
-Strong covalent bond - Weak intermolecular force - low melting point -low boiling point -Don't conduct electricity, no free moving ions |
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Explain the mnemonic O.I.L R.I.G |
Oxygen Is Loss Reduction Is Gain |
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What are the properties of group 1 metals? |
-Low melting point -Low density -Very soft |
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What is the order of reactivity for group one metals? |
Top of table is less reactive More reactive at the bottom Order is Lithium Sodium Potassium Rubidium Caesium Francium |
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What colour flame do these metals give off when burnt? Lithium Sodium Potassium |
Lithium=Red Sodium=Yellow Potassium=Lilac |
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What is group 1 called? What is group 7 called? |
Group 1 = Alkali metals Group 7 = Halogens |
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Halogen + Alkali metal = ? What happens when halogens and alkali metals react? |
SALT HAPPENS, or is produced |
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What is the reactivity rule in group 7? |
The more down you go in the group, the less reactive it is In order from most reactive: Fluorine Chlorine Bromine Iodine Astatine |
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What happens if a more reactive halogen reacts with a solution containing a less reactive halogen? |
The more reactive halogen displaces the less reactive halogen. e.g. Chlorine+Potassium iodide=Iodine+Potassium chloride |
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What type of structure do metals have? Explain this structure? |
-Metals have a crystal structure. -All metals have the same type of basic properties -They are all held together with metallic bonds. -Metallic bonds allow the electrons to move freely which makes a sea of de-localised electrons which means THEY CAN CONDUCT ELECTRICITY |
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What are the properties of metals? |
High melting point High boiling point High density High tensile strength Bendy Malleable Electrical conductors Thermal conductors |
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What is a superconductor? |
A metal which at low temperatures can conduct electricity without resistance occurring. |
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What happens if you remove the battery from a circuit that is made from a super conductor? |
The electrical current will contentiously loop throughout the whole of the circuit which is good as it allows the circuit to be infinite. |
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What can be made with super conductors? |
-Power cables which transmit electricity without any loss of power -Strong electromagnets without need for a constant power source -Very fast electric circuits |
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Disadvantages of super conductors? |
-Very hard getting things THAT cold as superconductors need extremely cold conditions -To make the extreme coldness it is very exspensive |
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Advantages of super conductors? |
-Work at extremely low temperatures -Resistance free |
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Where are transition metals in the periodic table? |
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What colours are these elements? Iron 2 Iron 3 Copper |
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What is thermal decomposition? |
When a substance breaks down into two or more other substances when heated. |
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What do transition metal carbonates give off when thermally depositioned? |
They break down into a transition metal oxide and carbon dioxide e.g. Copper carbonate = Copper oxide + Carbon dioxide This usually also comes with a colour change of the transition metal oxide |
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What is the test if carbon dioxide is given off? |
The lime water test, if the lime water turns milky then carbon dioxide is present. |
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What is a precipitation reaction? |
A precipitation reaction is when two solids react and an insoluble solid form in the solution. |
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What is the solid called in a precipitation reaction? |
A precipitate |
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What can precipitates be used for? |
They can be used to test for transition metals. The colours are in the table |
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Where do we get our water from in the United Kingdom? |
Surface waters; Lakes, Rivers, Reservoirs Groundwater: Aquifers( Rocks that trap water underground) |
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How is water treated? |
Filtration- a wire mesh screens out large twigs and then gravel and sand beds filter out any other solid bits Sedimentation- iron sulfate or aluminium sulfate is added to the water, which makes fine particles clump and settle at the bottom Chlorination- Chlorine gas is bubbled through to kill harmful bacteria and other materials |
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What impurities are found in water? |
-Nitrate residues from excess fertiliser in rivers and lakes which can cause health problems for people as it can prevent oxygen from going around the body -Lead compounds from old lead pipes which are poisonous -Pesticide residues from spraying pesticides near rivers and lakes. |
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How else can we get fresh water? |
Distillation can also be used to get fresh water . |
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What is the disadvantage of distillation? |
Distillation is expensive and not practical for producing large quantities of water. |
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How can you test for sulfate ions in water, explain the complete process. |
1) Add some dilute hydrochloric acid to the test sample 2) Then add 10 drops of barium chloride solution 3) if you see a white precipitate, There are sulfate ions in the sample. |
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How can you test for Halide ions in water, explain the complete process. |
1) Add some dilute nitric acid to the test sample 2) Then add 10 drops of silver nitrate solution 3) If halides ions are formed then these precipitates will form (Picture) Chloride is white Bromide is cream Iodide is pale yellow |
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Silver nitrate + Sodium chloride= AgNO3 + NaCl= Silver nitrate + Sodium bromide= AgNO3 + NaBr= Silver nitrate + Sodium iodide= AgNO3 + Nal= |
Silver chloride + Sodium nitrate AgCl + NaNO3 Silver bromide + Sodium nitrate AgBr + NaNO3 Silver iodide + Sodium nitrate Agl + NaNO3 |
