Group 1 metals are very reactive.
All Group 1 elements react with water to produce a metal hydroxide and hydrogen. This is the equation for the reaction between sodium and water:
sodium + water → sodium hydroxide + hydrogen
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
All Group 1 metal reacts with water. There are some common observations and some differences:
Group 1 metals all react in the same way, because each of them loses an electron to form a positive ion with a stable electronic configuration – a full outer shell.
For example, sodium loses one electron to form a sodium ion, Na+, with a full outer shell.
Half equation - Higher tier
This can be represented by a half equation:
Na → Na+ + e-
Group 1 elements become more reactive as we move down the group. These atoms are larger because they have more shells. The larger the atom, the further the outer electron is from the nucleus. The force of attraction between the nucleus and the electron is less than for smaller atoms, and the outer electron is lost more easily.