A technician demonstrates the reactions of different Group 1 elements with water.
State two observations that could be made when a small piece of potassium is added to a trough of water.
In another demonstration, the technician added a small piece of a different Group 1 metal to a trough of water. They noted that the reaction was less vigorous than that of potassium, and the metal did not melt into a ball, but instead floated and fizzed on the water surface. Identify the metal used in this demonstration.
When Group 1 metals react with water, they produce a flammable gas. A flame test of the resulting solution or the metal itself can also help identify the element. (i) Identify the gas produced when lithium reacts with water. (ii) Give the formula of the ion that produces a characteristic red color in a flame test.
When alkali metals react, each atom loses its single outer shell electron. For sodium and potassium, these processes are represented by the equations:
Na→Na++e− \text{Na} \rightarrow \text{Na}^+ + \text{e}^- Na→Na++e− K→K++e− \text{K} \rightarrow \text{K}^+ + \text{e}^- K→K++e−Explain, by referring to the electronic configurations of sodium and potassium, why potassium is more reactive than sodium.
