Periodic table groups

• Group 1 is called the alkali metals.
• Group 7 are called the halogens
• Group 0 is called the noble gases.
• The elements without a group are called the transition metals.
• Group 1 have 1 electron in their outer shell. Because they lose this in ionic bonding, they form positive ions.
• Group 7 have 7 electrons in their outer shell. This means they form negative ions because they need to gain 1 electron.
• Group 1 metals are very soft and react vigorously with water. They have low densities, have low melting and boiling points, are shiny/grey and produce hydrogen gas and hydroxides when reacted with water.
• Group 1 metal’s boiling and melting points decrease as you move down the group. However, their reactivity increases. This is because the electron in their outer shell moves further away from the nucleus as you move down. So, the force between the nucleus and the outer electron is reduced.
• Group 7’s melting and boiling points are low, but they increase going down the group. Their reactivity decreases going down the group also and this is because the force of attraction between the 7 outer electrons and the nucleus decreases.
• Group 7 are non-metals, are poor conductors of heat and electricity and are all diatomic. A more reactive halogen will displace a less reactive halogen.
• The transition metals are hard/strong, have high densities, have high melting and boiling points (except mercury), can form more than one ion, and are good conductors of electricity. They are not very reactive and form coloured compounds.
• The noble gases are non-metals, very unreactive and it is difficult to combine them with other elements.