GCSE Paper 1 Flashcards
What is the radius of an atom?
1 x 10 - 10m
Whats the radius of a nucleus?
1 x 10-14m
Def ionic bonding
When a metal and a not metal lose and gain electrons which causes them to be strongly attracted to each other
Def covalent bonding
When non-metals share electrons to become bonded together
What is the formula for ammonia?
NH3
How can you separate an insoluable solid from a liquid?
Filtration
How can you separate a soliable solid from a liquid? (2)
Evaporation
Crystallisation
When would you have to use crystallisation instead of evaporation
If the salt doesnt decompose when heated
What is simple distillation used for?
To seperate out solutions
How do you do simple distillation?
The solution is heated (lower boiling point solution evaporates first)
The vapour is then cooled and condensed down to a liquid
The rest of the solution is left behind
Whats the problem with simple distillation?
You can only use it to seperate things with very different boiling points
What is fractional distillation used for?
To seperate out a mixture of liquids
How does fractional distillation work?
The top of the flask is cooler than the bottom ensuring that only the lowest boiling point substance evaporates first as any others that evaporate will just cool and run back down the collumn.
Who thought of the plum pudding model?
JJ Thompson
Who was Ernest rutherford?
He proved the plum pudding model wrong and performed the alpha particle scattering test to show atoms had a nucleus
How was Rutherfords moedel different to Bohr’s model?
He had a field of negatively charged electrons instead of shells with electrons in
What was Bohr’s nuclear model?
He sadi that the atom had shells with electrons in, and none inbetween, his model is the same we have today (although he never theorised about protons and neutrons etc)
What further experiments on the structure of the atom were carried out?
Rutherford proved protons existed
James Chadwick discovered neutrons
Who was dimitri mendeleev?
Mendeleev left gaps in the early versions of the period table for undiscovered elements and also switched some of them if the properties didnt fit the group they were in. His predictions for undiscovered elements were very accurate
What compounds do alkali metals form with non metals?
Ionic
What happens when an alkali metal reacts with water?
The react vigorously
They produce hydrogen
They produce hydroxides (eg sodium hydroxide)
What happens when an alkali metal reacts with chlorine?
They react vigorously and form white salts called metal chlorides
Other than chlorine and water, what else do group 1 metals react with?
Oxygen to produce metal oxides.
How is reactivity arranged in the halogens?
They get less reactive as you go down the group
Describe the properties of Flourine
Very reactive
Yellow gas
Poisonous
Describe the properties of chlorine
Fairly reactive
Dense, green gas
Poisonous
Describe the properties of bromine
Dense, red/brown volatile liquid
Poisonous
Describe the properties of iodine
Dark grey crystalline solid OR purple vapour
How are molecules in the halogens found?
In pairs
How are the melting and boiling points of the halogens affected as you move down the group?
They are found in pairs
What is a halide?
An ion of a halogen
Describe the elements in group 0
They all have 8 electrons and are all inert (stable)
They are monatomic and come alone
They are non flammable
They are colourless
What patterns are there in the properties of the noble gases?
Their boiling points increase as you go down the group due to more electrons and greater intermolecular forces.
What is ionic bonding?
The transfer of electrons between atoms
What kind of structure do ionic compounds have?
Regular lattice structure
What properties do all ionic compounds have?
High melting points
High boiling points
Do not conduct electricity as a solid but the ions can move in a liquid so they do as a liquid
Some dissolve in water and carry electric charges
How do you find the empirical formula from an ionic lattice?
- Identify the elements
- Identify what ions those elements become
- Balance the formula for the ions
Who can form a covalent bond?
Only non metals
How are covalent bonds very strong?
The positive nuclei are attracted to the shared electrons by electrostatic forces
What is the formula for methane?
CH4
What are the properties of simple molecular structures?
The forces in the binds may be strong but the intermolecular forces are weak
Low melting and boiling points
Most are gases or liquids at room temp
Dont conduct electricity as they aren’t charged
What state are polymers in at room temp?
Solid
What are giant covalent structures?
Macromolecules
Why are gisnt covalent structures so strong?
All of the atoms in the structure are bonded together by strong covalent bonds
Def allotrope
A different structural form of the same element in the same physical state
Whats the formula of a buckminster fullerene?
C60
What can buckminster fullerenes be used for? (3)
Drug delivery
Catalyst (large surface area)
Lubricants
What is a nanotube?
A tiny carbon cylinder (allotrope)
What are some properties of nanotubes? (4)
Conduct heat
Conduct electricity
Have a high thermal temp
High tensile stength
What are some uses of nanotubes? (2)
Used to strengthen materials
Used in electronics
How is metallic bonding different to the others?
Contains a delocalised electron which causes attraction between the positive metal ions and electrons creating strong intermolecular forces.
What three things affect the strength of intermollecular forces
Material (structure and type of bonding)
Temperature
Pressure
Whats the formula to calculate the moles?
Number of moles = mass in grams / relative formula mass
What’s the relation between the limiting reactant and the products
The amount of limiting reactant used is directly proportional to the amount of rectant formed. Half the limiting reactant, half the products made
Whats the equation for concentration?
Concentration (g/dm3) = mass of solute (g) / volume of solvent (dm3)
How do you calculate decimeters cubed?
Divide centimeters cubed by 1000 (or ml)
How do you calculate mass in relation to concentration?
Mass = concentration x volume
Whats the neutralisation reaction between an acid and a base?
Acid + base = salt + water
What happens to an acid in a solution?
They ionise and produce H+ ions (protons)
What difference occurs when a strong and weak acid ionise in water?
A strong acid will fully ionise but a weak acid will not
What does it mean that a weak acid doesnt fully ionise in water?
It creates a reversible reaction and sets up an equilibrium
Whats the difference between a strong acid and a concentrated acid?
A strong acid is a measure of what proportion of the molecules ionise in water but the concentration is just how much acid there is in a certain volume of water.
How do acids and metal oxides/hydroxides react?
Acid + metal oxide/hydroxide = salt + water
How do acids and metal carbonates react?
Acid + metal carbonate = salt + water + carbon dioxide
What can you use to make a soluable salt?
An insoluable base mixed with an acid
How do acids and metals react?
Acid + metal = salt + hydrogen
How do metals react with water
Metal + water = metal hydroxide + hydrogen
What is oxidation and reduction?
Oxidation is the gain of oxygen
Reduction is the loss of oxygen
When can you use reductin with carbon
You can reduce any element - (iron, zinc, copper) - lower than carbon on the reactivity series to nick its oxygen and leave you with just the ore.
What makes a redox reaction
Electrons being transferred
What are oxidation and reduction in a redox reaction?
Oxidation is the loss of electrons
Reduction is the gain of electrons
OIL RIG
What does an ionic equation show?
All of the substances that are oxidised or reduced in the reaction
What ore is aluminium found in?
Bauxite
How is aluminium’s high melting point countered in electrolysis?
It is mixed with cryolite to reduce its melting point
How can you test for chlorine
It bleaches damp litmus paper white
How can energy transfer be measured
By measuring the temperature of recants and then mixing them together and taking a mew temperature to see if it is higher or lower.
What transfer of energy occurs in an exothermic reaction (bonds)
When new binds are formed energy is released, creating heat
