Chemistry paper 1
Cards (36)
- Exothermic reactions transfer energy to surrounding
- Combustion is exothermic
- Oxidation is exothermic
- Endothermic reactions take energy in from surroundings
- Activation energy is the minimum amount of energy needed for a reaction to take place
- Electrolyte is the liquid that conducts electricity
- Alkaline batteries are non rechargeable
- Molecules are 2 or more atoms held together by chemical bonds
- Compounds are two or more different elements held together by chemical bonds
- Mixtures are two or more substances not chemically combined together
- Filtration separates insoluble solids from liquids
- You can separate soluble solids from liquids using evaporation or crystallisation
- Simple distillation separates liquids from a solution
- Fractional distillation separates mixtures of liquids
- John Dalton described atoms as solid spheres
- JJ Thompson came up with the plum pudding model - atoms contain negatively charged particles called electrons
- Rutherford discovered the nucleus , protons and neutrons
- Bohr suggested electrons orbit the nucleus in shells
- In order for atoms to be stable they need a full outer shell
- The periodic table is arranged in order of increasing atomic number
- The group number tells you how many electrons are in the outer shell
- Group 1 are alkali metals they all react badly with water and they are more reactive as you go down the group
- Group 7 elements are called halogens and they become less reactive as you go down the group
- Group 0 elemelements are noble gasses and they have full outer shells making them very unreactive
- Metals are on the left side of table
- Atomic number is always smaller than mass number
- Mass number = protons + neutrons
- Proton number = atomic number
- Atoms in each period have the same number if shells
- Metals are malleable good conductors and have high melting and boiling point most of the time they are shiny
- Non-metals have low density and brittle and bad conductors they have low melting and boiling points
- Transition metals are lustrous, hard, strong, ductile, malleable, magnetic and can be coloured or silver white
- Solid to gas is sublimation
- Ionic bonding is metal and non metal
- Covalent is non metal
- Alloys are mixtures of metals