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Chemistry - Atoms, Elements, Compounds, Mixtures - Coggle Diagram
Chemistry - Atoms, Elements, Compounds, Mixtures
Atom
smallest part of a substance
radius of about 0.1 nm
Nucleus
protons and neutrons
centre
positive charge due to protons
almost whole mass is concentrated in nucleus
Electrons
move around nucleus in electron shells
negatively charged
tiny
Relative mass / charge
Proton
Relative mass
1
Relative Charge
+1
Neutron
Relative Mass
1
Relative Charge
0
Electron
Relative Mass
very small
Relative Charge
-1
Atoms are neutral
number of electrons = number of protons
charges are same size but opposite
cancel out
Symbol
Atomic Number
number of protons
Mass Number
total number of protons + neutrons
Neutrons = Mass number - Atomic number
Element
a substance made up of just 1 type of atom
e.g. oxygen
number of protons that decide what type of atom
represented by symbols
Isotopes
different forms of the same element
same number of protons, different number of neutrons
same atomic number, different mass numbers
many elements can exist as many different isotopes
relative atomic mass is used instead of mass number
Compounds
substance consisting of 2 or more elements chemically combined
e.g. H2O, CO2
atoms of each element are in fixed proportions throughout compound
held together by chemical bonds
properties are totally different from properties of original element
represented by formulas
Mixture
contains 2 or more elements or compounds not chemically combined
e.g air, salt water
no chemical bond
easily seperated
seperated by physical methods