hemija

1. chemistry
   Sutra imamo kontrolni iz hemije. — We have a chemistry test tomorrow.
   Moja sestra studira hemiju u Beogradu. — My sister studies chemistry in Belgrade.
2. colloq. (between people) chemistry; mutual attraction
   Između njih dvoje odmah se osetila hemija. — You could feel the chemistry between them right away.
3. colloq. (of food, products) chemicals; artificial additives
   Ovaj sok je sama hemija, nema u njemu voća. — This juice is nothing but chemicals, there's no fruit in it.

'Hemijska' (olovka) means a ballpoint pen, not chemistry.