C1 atomic structure Flashcards
What is an atom
Tiny particles that make up everything in the world
What is an element?
One type of atom, on its own or joined to another atom of the same type. E.g: everything on the periodic table
What is a mixture?
A group of 2 or more compounds. Elements or compounds mixed together but not chemically bonded.
What are the subatomic particles in an atom
- protons
- neutrons
- electrons
What 2 subatomic particles are in the nucleus of an atom?
Protons and Neutrons
What subatomic particle is found in the energy levels/shells?
Electrons
What are the 3 subatomic particles mass, location and charge?
Subatomic particle Mass location charge
Proton 1 Nucleus +1
Neutron 1 Nucleus 0
Electron Very small Shells -1
What is an ion?
An atom or group of atoms that has gained or lost electrons
What is the atomic number?
Shows how many protons there are (Same no. of protons as electrons)
Bottom number on element symbol
What is the mass number?
The total number of protons and neutrons in the atom
How do you find the number of Neutrons?
Subtract the atomic number from the mass number
What is the method of Sand, salt and water separation method?
Pour mixture into funnel and wait for it to go through into the beaker (Will remove sand on filter paper). Put remaining water in evaporating dish and place dish on gauze above Bunsen burner. During this place a lid or object on top of evaporating dish to collect the water
How do we know a chemical reaction has occurred?
- Acid and Alkali levels change
- Colour change
- Gas is given of
- Temperature change
- Fizzes or bubbles
What are isotopes?
Different forms of the same element, which have the same number of protons but a different number of neutrons E.g. Carbon
What is ionic bonding?
between a metal and a non-metal e.g. Sodium chloride, magnesium oxide, and calcium oxide
What is covalent bonding?
Between 2 non-metals e.g. hydrogen, chlorine gas and water
What is the conservation of mass?
mass of reactants = mass of products
What is a solute?
The solid that is dissolved in a liquid (Solvent)
What is a solvent?
The liquid that the solid is dissolved into
What is a solution?
A mixture with the solute dissolved in the solvent
What is chromatography used for?
It separates mixtures of coloured compounds includes dyes, ink and colouring agents in food. Can be used for forensic scientists =, performance enhancing drug tests, quality of alcohol and testing of horsemeat scandal
Why do atoms have no overall charge?
The number of protons and electrons is the same. The charge is cancelled out
Proton +1
Electron -1
What is the number of electrons allowed in each energy level/shell?
2,8,8,2
How does the periodic table structure work?
- The groups go down in vertical columns
- Group number shows how many electrons are in the outer shell
- Elements in the same group have similar properties
- Periods go across the table
- Period number states how many shells there are
Why are elements in group 0 very unreactive?
They will have full outer shells
What was John Daltons thought of the atom?
- Solid spheres
- Different spheres made up the different elements
What was J J Thomsons view of the atom?
- Atoms weren’t solid spheres
- His measurements of protons and neutrons showed that an atom must contain even smaller negatively charged particles, electrons
- Now knows as
Plum pudding theory - The atom was a ball of positive charge with electrons stuck in it
What was Rutherfords view of the atom?
- fired positively charged alpha particles at a sheet of gold
- Some went through the sheet, others were deflected
nuclear model- A tiny positively charged nucleus at centre,
cloudof negatively charged electrons surrounds it
What was Bohr`s view of the atom?
- suggested all electrons were contained in shells
- Electrons orbit the nucleus in fixed shells and aren’t in-between
What is considered a happy atom?
Full outer shell
The charges of all groups
Group 1 - +1
Group 2 - +2
Group 3 - +3
Group 7 - -1
Group 6 - -2
Group 5 - -3
What is the method of chromatography?
- Draw pencil line near the bottom of filter paper
- Add different spots of ink to line and place the sheet in a beaker of solvent e.g. water
- Make sure ink isn’t touching the solvent
- The solvent will seep up the filter paper
We use a pencil line and not pen because the pen will run, whereas pencil is insoluble
What is filtration and how do you do it?
- Separates insoluble solids from liquids
- Can be used in purification
- Using filter paper, it collects the insoluble solids allowing the liquid to seep through to a beaker
What is the method of crystallisation?
- Pour solution into an evaporating dish and gently heat
- Once some of the solvent has evaporated or when you see crystals begin to for, remove the dish from heat and leave to cool
- Filter the crystals out of the solution, leave in warm place to dry
What is the method of evaporation?
- Pour solution into an evaporating dish
- Slowly heat the solution, solvent will evaporate and the solution will get more concentrated - crystals will begin to form
- Keep heating evaporating dish until all that’s left is dry crystals
What is distillation?
Used to separate mixtures which contain liquids
2 types are simple and fractional
What is simple distillation and what is the method?
- For separating out a liquid from a solution
1. Solution is heated, the part of the solution that has the lowest b.p evaporates first
2. The vapour is then cooled, condenses and is collected
3. Rest of the solution is left in the flask
What can you use simple distillation for?
To get pure water from saltwater - after simple distillation, only salt will be left behind as residue
What is a problem with simple distillation?
Only can be used to separate things with very different b.p - if the temp goes higher than the b.p of the substance with the higher b.p they will mix again
Why can fractional distillation be used instead of simple distillation?
When there is a mixture of liquids with similar b.p
What is the method of fractional distillation?
- Put mixture into a flask and stick a fractionating column on top, then heat it
- The different liquids will all have different b.p - so will evaporate at different points
- The liquid with the lowest b.p evaporates first - when the temp on the thermometer matches the b.p of the liquid it will reach the top of the column
- Liquids with higher b.p might also start to evaporate, but the column is cooler towards the top so they will only get part of the way up before condensing and running back down the flask
- When the first liquid has been collected, you raise the temperature until the next one reaches the top
