Chemistry - unit 1

  • Created by: Flossy15
  • Created on: 03-01-19 21:30
  • Rate = Change in property / Change in time
  • There are 7 Diatomic elements:

- Hydrogen  - Nitrogen  - Oxygen - Fluorine - Chlorine - Iodine - Bromine

  • Proton has a charge of 1+ and its relative mass is 1
  • Neutron has a charge of 0 and its relative mass is 1
  • Electron has a chage of -1 and its relative mass is almost 0
  • The atomic number is proton = electrons (only in a neutral atom)
  • The mass number is the number of protons + the number of neutrons 
  • The top number in an nuclide symbol is the mass number and the bottom is the atomic number.
  • Isotope are atoms that have the same atomic number but a different mass number
  • All metals are + 
  • All non metals are -
  • ionic bonding is between non metals and metals 
  • Ionic bondingoccurs when electrons are transferred from one atom to another atoms
  • The ionic bond is formed so that both the metal and the non metal become more stable.
  • Ionic lattice is when a solid ionic compounds arrange themsevles into alttices becase of the attraction of opposite charges
  • Covalent bonds are formed by atoms SHARING electrons.  They are formed when non metals bond together.
  • All the 7 diatomic elements are bonded covalently 
  • covalent network is like all bonds between normal covalent bonds but the huge network structure gives the substance its strength.
  • Diamond - all 4 electrons are held in a strong covalent bond
  • Graphite - 3 electrons are held in strong covalent bonds forming layer. the 4th electron is delocalized.
  • Covalent bonds tend to have low melting points.  This is because to melt the covalnet substance, the molecules merely need to be separated from each other. 
  • There are only weak intermolecular forces keeping the molucles together.
  • Ionic compounds have high melting points.  This is because the ionic bonds have to be broken down in order to melt it, which willrequire a lot of energy.
  • Diamond has


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