Question 8 5 pts
A solid, orange PURE SUBSTANCE (K2Cr207) was heated yielding a
colorless gas and a green solid. What kind of material was heated?
O a solution
O an element
O a compound
O a mixture

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!