Groups in the periodic table

• Group 1 metals are called the Alkali metals. They are soft and have low melting and boiling points.
• Alkali metals are shiny when freshly cut
• Alkali metals are good conductors of heat and electricity.
• The reactivity of alkali metals increases down the group.
• Lithium fizzes steadily and form a red flame when heated in air
• Sodium melts into a ball from the heat released in the reaction and fizzes rapidly
• Sodium gives off a yellow flame.
• Potassium gives off sparks and the hydrogen produced burns with a lilac-coloured flame
• Lithium, sodium and potassium are less dense than water, so they float.
• Lithium, sodium and potassium are stored in oil, this is to keep air and water away.
• Alkali metals lose their outer electrons easily and form positive ions.
• The number of shells in alkali metals increases as you go down the group. The attraction between the nucleus and outer electron weakens.
• Group 7 elements are known as the Halogens.
• Going down group 7, the melting and boiling points increase.
• Going down group 7, the intermolecular forces between molecules become stronger and more heat energy is needed to overcome these.
• The reactivity of the elements decreases down group 7.
• sodium + water --> sodium hydroxide + hydrogen
• Halogens gain one electron to complete its outer shell when reacting with a metal or hydrogen
• Halogens gain electrons less easily so they are less reactive than metals.
• Fluorine is more reactive than chlorine.
• Halogens gain ions and have a negative charge, they are called halides.