"Chazaq" (courage/strength) written in Hebrew?

Hi, I want to get a tattoo of the Hebrew word for courage/strength. I've done quite a bit of research and from what I can understand the word "Chazaq" is the best word in Hebrew to convey that meaning. Can someone who know's Hebrew fluently please write this word in Hebrew letters for me? I don't know if Hebrew uses feminine/masculine forms or anything like that and I want it to be 100% correct. Also, why are vowel marks used sometimes and sometimes not, and does it make a difference to the meaning of the word? And, if this is not the correct word for what I'm going for, please suggest otherwise. Thanks!