Explain the trend in reactivity of group 1 metals.

Going down the 1st column of the periodic table the group 1 metal have increasing numbers of electrons.All group 1 metals have a single electron in their outer shell and with an increasing number of electrons more shells are required that are spaced further and further from the nucleus.The electrostatic attraction between the positive nucleus and the outer electron therefore gets weaker the higher the atomic number which makes it easier to remove the outer electron to form an ion. Therefore making the metal more reactive.