Name the following

A metal that gives a lilac flame.

1. Metals are the elements that have the tendency to lose electrons present on them and thereby forming positively charged elements.
2. The metals show colour to a flame when they lose electrons present in its valence shell thereby forming a positively charged ion.
3. The element that shows a lilac colour to the flame is Potassium($\mathit{K}$) by the loss of electrons.

So the metal that gives lilac flame is potassium (K).