C1 atomic structure Flashcards
what is the relative mass for protons neutrons and electrons
proton- 1
neutron- 1
electron- 0
what is the charge for protons neutrons and electrons
proton- +1
neutron- 0
electron- -1
what is equal in an atom
protons and electrons
what is the overall charge of an atom
0 because the charge of a proton and electron cancel out
what is the mass number
top number- total number of protons and neutrons
what is the atomic number
bottom number- amount of protons
what is an element
substance made up of atoms with the same number of protons
what is an isotope
different forms of the same element which have the same number of protons but a different number of neutrons- different mass number
what is a compound
chemically bonded substances formed from two or more elements in fixed proportions
how do atoms form bonds
atoms giving away, taking or sharing electrons
what is a mixture
a mix of elements or compounds with no chemical bond between the different parts
how can you seperate a mixture
filteration, crystallisation, simple distilstion, fractional distillation and chromatography
what is filteration
separates an insoluble solid from a liquid
what is evaporation
separates a soluble salt from a solution- leaves dry crystals
what is simple distillation
used for separating a liquid from a solution- solution is heated and the part of the solution with the lowest boiling point evaporated first, the vapour cools and condenses
what is fractional distillation
seperates a mixture of liquids with different boiling points
what did john dalton describe atoms as
19th century- described them as solid spheres
what did jj thompson describe atoms as
1897- created plum pudding model- a ball of positive charge with electrons stick in it
how did rutherford prove the plum pudding model wrong
1909- alpha scattering experiment, fired positively charged alpha particles at sheet of gold- some deflected backwards so created nucleus in centre with mostly empty space
who created the most recent nucleus model
neil bohr
