Exchanging ideas about science is called

Communication.

When people exchange ideas about science, they are communicating with one another to both share and obtain knowledge. Collaboration is a large part of this communication, as the exchange of these ideas often leads to new discoveries and inventions.

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.