Topic 1; Atomic Structure And The Periodic Table Flashcards
What are the methods that mixtures can be separated? (5)
Fractional distillation, simple distillation, filtration, crystallisation, chromatography
Describe simple distillation
- separates liquid from solution
- liquid boils off and condenses in condenser
- thermometer reads BP of pure liquid
- get to keep liquid
Describe crystallisation/ evaporation
- separates dissolved solid from solvent (salt from water)
- solution is heated until saturated solution is formed
- cool down solution and solid starts to crystallise
- crystals collected via filtration
Describe fractional distillation
- separates liquids from other liquids
- uses fractioning column that is hot at bottom and cold at top
- liquids condense at different heights
Describe filtration
- separates insoluble solid from liquid
- residue gets caught in filter paper
- filtrate is substance that comes through paper
Describe chromatography
- separates mixture of substances in a solvent
- paper with spot into beaker with solvent
- solvent rises
Describe the plum-pudding model
Atom is a ball of positive charge with an electron embedded in it
Describe the Bohr model
Electrons orbit nucleus in specific shells
What did james Chadwick provide evidence for?
Proof of neutrons in nucleus
What is an atom’s nucleus made up of?
Protons and neutrons
Why do atoms have a neutral charge?
They heaven an equal number of protons and electrons
What is the name given to the number of protons in the nucleus?
Atomic number
What is the mass number?
Total number of protons and neutrons
What is an isotope?
Atom of the same element with the same proton number but different neutron number
What are ions?
Charged particles formed when atoms gain or lose electrons
