C1 Atomic structure Flashcards
All substances are made from what?
Atoms
What does an element contain?
only one type of atom
What is Group 1 called?
The alkali metaks
What is group 2 called?
The alkaline earth metals
What is group 7 called?
The halogens
What is group 0 called?
The noble gases
What are the elements between group 2 and 3 called?
transition metals
What do groups in the periodic table have in common?
similar chemical properties
Where are metalloids or semi-metals found?
Next to the metal/non-metal divide
What is a compound?
A compound is a pure chemical substance made of two or more different chemical elements.
What are all atoms made up of?
a tiny central nucleus with electrons orbiting around iy
What do chemical equations show?
The reactants and the products
Can you draw the product of hydrogen + oxygen
water
Can you do a symbol equation for CaCO3 ->
CaO + CO3 - its already balanced
What does an equation being balanced mean?
There is the same number of each type of atom on both sides of the equation.
Why is an equation being balanced important?
Because atoms cannot be created or destroyed in a chemical reaction
This also means that:
The total mass of the products in a reaction is equal to the total mass of the reactants
What is ‘The total mass of the products in a reaction is equal to the total mass of the reactants’ called?
the law of conservation of mass
What are state symbols
Symbols which show what state the substance is in
What is solids state symbol
(s)
What is liquids state symbol
(l)
What is gases state symbol?
(g)
What is aqueous symbol?
(aq)
Add the state symbols to CaCO3 -> CaO + C02
CaCO3(s) ->CaO(s) + CO2(g)
What is an aqueous solution?
substances dissolved in water
Can you balance the equation
H2 + 02 -> H20
2H2 + O2 -> 2H20
What are differences between a compound and mixture
-Mixtures has a fixed composition - Mixtures have no fixed composition
-Mixtures must be used to separate the elements in a compound - Mixtures, the different elements or compounds in a mixture can be separated again more easily
-Compounds have chemical bonds between atoms of different elements in the compound - Mixtures, there are no chemical bonds between atoms of the different substances in a mixture
What are the 4 physical separation techniques?
Filtration
Crystallisation
Distillation
Chromatography
What type of substances can filtration separate?
An insoluble solid and a soluble liquid
Give an example of what would filter
Sand and water
Can you draw and label a filtration aparatus
What type of separation could you obtain a sample of pure salt from a salt solution?
crystallisation
What type of substances can crystallisation separate?
a soluble solid and a solvent
Can you draw and label a crystallisation aparatus
When should heating be stopped during crystallisation?
When the solution is at the point of crystallisation. This is when small crystals first appear around the edge of the solution or when crystals appear in a drop of solution extracted from the dish with a glass rod
How can you collect pure water from sea water?
Distillation
What happens in simple distillation?
A solution is hated and boiled to evaporate the solvent. The vapour given off enters a condenser. This is an outer glass tube with water flowing through it acts as a cooling ‘jacket’ around the inner glass tube from the flask. here the hot vapour is cooled and condensed back into a liquid for collection in a receiving vessel
What happens to any solid in simple distillation?
They will remain in the heated flask
Can you draw and label a simple distillation aparatus
What type of substances can fractional distillation separate?
Miscible liquids
What does miscible mean?
Describes liquids that dissolve in each other, mixing completely. They don’t form separate layers as seen in mixtures of immiscible liquids that have been allowed to settle