chemistry revision Flashcards
what is the atom made up of?
the atom is made up of protons(positively charged) Neutrons (neutral) and electrons (negatively charged)
facts about electrons (give 3)
1) they move around the nucleus in shells
2) they are tiny
3)they virtually have no mass
true or false?
can ions be positive AND negative?
true
yes they can! negative ions from when atoms gain electrons and positive ions form when atoms loose electrons
true or false?
are group 1,2 and 3 elements metals
true
yes they are they loose electrons to form positive ions
what are groups 5,6and 7
they are non-metals
they gain electrons to form negative ions!
atoms to learn
Ag+, Fe2+, pb2+, cu2+, fe3+, zn2+
what are ionic compound?
ionic compounds are made up of a positively charged part and a negatively charged part. the overall charge of ANY ionic compound is 0 so all the negative charges in the compound musts balance all the negative charges.
what is filtration
Filtration is used to separate and insoluble solid from a liquid. It can be used in purification too!
what is crystallisation?
crystallisation separates a soluble solid from a solution
what is chromatography?
chromatography is another method used by chemists to separate out mixtures. You can use paper chromatography to separate dyes
what is distillation?
Distillation is used to separate mixtures that contains liquids there are 2 types we need to know- simple and fractional.
simple distillation is….
used to separate out solutions.
fractional distillation is ….
used to separate out mixtures of liquids. the fractioning couloum has glass rods
