# Strangeness Conservation

I am stuck as to how to prove that strangeness is conserved in electromagnetic and strong interactions, while it is not conserved in weak interactions. I know that this can be shown by studying the terms of the standard model Lagrangian, but I have no idea as to how I should proceed.

• Write down all vertices involving at least one strange quark and a gauge boson. – Cosmas Zachos Jun 13 at 0:07
• Hint: which interactions change quark flavor? – probably_someone Jun 13 at 7:58