1) High melting points, high boiling points
2) Conductive in liquid form
3) Hard, but brittle in solid form
Answer:
Both are highly reactive.
Explanation:
A has 1 valence electron D has 3
A is sodium D is aluminum
Can you give some choices?
I'll tell you a few that are monatomic, the Noble gases:
Helium
Neon
Argon
Krypton
Xenon
The scientific method use, and thus going "for, the idea of following the ideal of scientific evidence.