chem paper 1

• what is a atom


  an element which cannot be broken down
• what is a compound

  two or more elements chemically bonded
• what is a mixture

  different atoms/compounds not chemically bonded
• what is a element 


  a substance containing only one type of atom
• what does filteration do

  removed large, insoluble particles from a liquid
• what does evapouration do

  leaves behind crystals of a dissolved substance
• what is distillation

  condensing the evapourated solvent and collectinf it
• what is fractional distillate

  the separation of liquids due to their different boiling points
• what does chromatography do

  it causes substances to rise up the paper due to capillary action
• can solids be compressed

  no
• can liquids be compressed

  no
• can gasses be compressed

  yes
• what are the particles like in a solid

  in a regular arrangement/ fixed position
• what are the particles like in a liquid

  no regular arrangement/ able to move
• what are the particles like in a gas

  far apart/ free to move
• what is it when a solid changes to a gas

  sublimation
• who created the plum pudding model

  JJ Thomson
• what did ernest rutherford discover

  that the neucleus was small and positively charged
• what did neils bohr say

  electrons exist in shells
• what did james chadwick say

  neucleus must contain neutrons and protons
• charge of a proton

  +1
• charge of a neutron


  0
• charge of a electron

  -1
• mass of a proton

  1
• mass of a neutron

  1
• mass of a electron

  0
• what is a isotope

  same element but different number if neutrons
• whats the atomic number

  the number of protons in a neucleus
• whats the mass number?

  number of protons and neutrons in a neucleus
• how were the elements originally ordered in the periodic table

  atomic weight
• what did Dmitri Mendeleev do on his table

  leave gaps for undiscovered elements
• electrons fill up in the order of what

  2,8,8,2
• why do metals donate electrons

  to gain an empty shell to form positive ions
• why do non metals accept electrons

  to gain a full shell
• what can non metals form

  negative ions
• atoms in group 1 are called what

  alkali metals
• atoms in group 7 are called what

  halogens
• group 0 elem are called what

  noble gases
• are group 0 atoms reactive

  not at all
• what can transition metals do

  donate different numbers of electrons