Hafnium - It’s a metal that sounds like 'have fun.' Your teacher doesn

It’s a metal that sounds like 'have fun.' Your teacher doesn’t know what it is. He just said it's cool and that’s why it’s on the periodic table.

I used Hafnium in my science project and got a C because I forgot what it was.

My friend called Hafnium 'have fun' and got a gold star for being funny.

I told my teacher Hafnium is a metal and he said, 'So is your brain after this class.'