GCSE Year 10 AP4 Flashcards
Compounds definition
When two or more different elements chemically react together. Not easily separated and the properties are completely different to the original elements.
Element definition
Made up of one type of atom.
Mixture definition
When two or more different elements are mixed together - easily separated and properties are a mixture of the different elements.
Isotopes definition
Different atomic forms of the same element e.g. Iron II and Iron III
What are the different subatomic particles?
Electrons - found in the shells, mass: 0, charge: -1
Protons - found in the nucleus, mass: 1, charge: +1
Neutrons - found in the nucleus, mass: 1, charge 0
What are the vertical columns of the periodic table?
Groups - shows the number of electrons in the outer shell, so elements in the same group have similar properties
What are the horizontal columns of the periodic table?
Periods - show the number of shells
What is the electron arrangement in the shells?
2, 8, 8
What are the different parts and how do you work out the number of neutrons, protons, and electrons from atoms in the periodic table?
12
C
6
12 represents the mass number, mass number - atomic number = number of neutrons
6 represents the atomic number, it is the number of protons and electrons
What is an ionic bond and what properties does it have?
Between a non-metal and metal. Giant ionic structures which form a regular lattice arrangement.
High melting and boiling point - very strong electromagnetic forces between the ions which are hard to break.
Conducts electricity when it’s dissolved in a solution - the ions separate and the electrons are free to move so they carry the current.
What is a simple covalent bond and what are its properties?
Between a two non-metals. Involves sharing of electrons.
Low melting and boiling points - weak intermolecular forces which are easy to break.
Don’t conduct electricity - no free electrons to carry the charge.
What is a giant covalent bond and what are its properties?
Very high melting points - lots of strong covalent bonds to be broken.
Graphite does conduct electricity - free electrons.
What are the properties of metallic bonds?
High melting and boiling points - strong bonds
Good conductors of electricity - free electrons
Malleable and ductile - free electrons allow atoms to slide over each other
Atoms definition
Atoms make up everything.
Shape memory alloys definition
Alloy which can deform and return to its original shape e.g. Frames for glasses.
Nanoparticle definition
A very small particle/structure between 1 and 100nm in size.
Polymer definition
Monomer must have a double bond.
This double bond breaks and the monomers join together to form very long chains - polymers.
What is low density poly(ethene)?
Made with a high temperature of about 200 degrees & high pressure.
Form branched chains which cannot stack together easily.
What is high density poly(ethene)?
Made with a low temperature of about 60 degrees, low pressure and a catalyst.
Forms straight chains which can stack together easily.
What is a thermosoftening polymer?
A polymer which softens when heated.
It has a low melting point.
What is a thermosetting polymer?
A polymer which is set once made.
It has a high melting point.
How do you do mole calculations?
Work out the number of moles of what you have a mass of: no. of moles = mass / Mr
Then work out the ratio.
Then work out the mass you need: mass = no. of moles x Mr
How do you work out the yield?
% yield = (actual mass/theoretical mass) x 100
How do you increase the rate of reaction?
Increase the…
Temperature
Concentration
Surface area
Or add a catalyst
How can you measure the rate of reaction?
Precipitation
Change in mass
The volume of gas given off
Rate of reaction = amount of product formed / time
How can you achieve more collisions to increase the rate of reaction?
Higher temperature - particles move faster
Higher concentration - more reactant, so collisions between important particles are more likely
Larger surface area - the particles around the surface will have more area to work on, so there will be more useful collisions
Catalyst increases the number of successful collisions - lower the activation energy
How can you achieve faster collisions to increase the rate of reaction?
Increase the temperature - particles have more energy
What is a catalyst?
A substance which changes the speed of a reaction without being changed or used up.
What is an exothermic reaction?
A reaction which gives out energy to the surroundings, usually in the form of heat and usually shown by a rise in temperature.
What is an endothermic reaction?
A reaction which takes in energy from the surroundings, usually in the form of heat showing a fall in temperature.
What is a reversible reaction?
A reaction where the products of the reaction can themselves react to produce the original reactants.
What is an acid?
A substance with a pH of less than 7. Form H+ ions in water.
What is a base?
A substance with a pH of greater than 7.
What is an alkali?
A base that dissolves in water to form OH- ions.
acid + base ->
H+ + OH- ->
salt + water
H2O
