Since certain chemicals react well together, we can use that image to describe how people interact well. They are the right "chemicals": they have "chemistry". So you could use it for any relationship - mainly men+women, but also friends and perhaps family members. A pair of movie actors who perform well together are described as having "on-screen chemistry". An alternative is "dynamic"(as a noun), which is normally used for groups. "Our household has a good dynamic", meaning you all work well together, and there's a good active energy between everyone. Someone moving out, or a new person moving in could change or disrupt the "dynamic".

hi mami, in a way, a good 'chemistry' implies to what is known to be a "perfect blend" between man and woman. this is the point where the 'couple' or 'lovers' can relate to each other. in fact, 'chemistry' can be applied to any partners whether they are your friends or families. should you want to win to a dance contest with your brother or sister for instance, you've got to have a good chemistry. :)

I think it is common to use between friends as well as girlfriends/boyfriends, but not family.

Yes you can use it for anybody....But I disagree with Peechey a little bit (with due respect). the word chemistry can also be used in negative sense, when interaction is not very well. For example; "We can't move together, our chemistry is different".

This is the first time that i've heard this word related man and woman,i'd like to konw the answer too.