Answer:
I think the answer is C but you might need a second opinion on this answer
Answer:The Geocentric and the Heliocentric models are descriptions of the universe known at the time when these models were developed. The main difference between the two models is the perceived center of the known universe. According to the geocentric model, Earth is the center of the known universe
Explanation:I answerd the question before in Earth Science
The reactivity of a metal is determined by how tightly the metal holds onto the electrons in the outermost energy levels (valence electrons)
Http://www.chem4kids.com/files/elem_pertable.html this should help.
