groups in the periodic table

• the first part of an equation are the reactants, the second half are the products
• metallic properties


  sonorous (makes sound)

  malleable

  conducts heat and electricity

  ductile (drawn into long wires

  lustrous (shiny)

  hard

  high density

  high melting and boiling points
• diatomic elements


  hydrogen (O2)

  oxygen (O2)

  nitrogen (N2)

  fluorine (F2)

  Chlorine (Cl2)

  bromine (Br2)

  iodine (I2)
• valence electron - an electron on the outermost shell of an atom
• metals in group 1 have 1 valence electron
• the first shell in an atom can hold up to two electrons
• every electron shell 2+ can have up to 8 electrons
• group one reactivity goes down
• alkali metals are...


  very soft

  only lustrous after being cut

  very reactive, react with water
• halogen - elements that are one electron from having a full outer shell (group 7 elements)
• halides - a negatively charged halogen, they have gained an electron from reacting with another substance
• the reactivity of group 7 elements go down as the number of electrons they have get larger, this is because the outer electrons are further away from the nucleus, making it harder for the nucleus to draw them in
• intermolecular forces - forces between molecules that hold them together and are responsible for the properties of the substance
• group 7 elements have 7 valence electrons