hydrogen and helium and the most abundant elements in a nebula.
Answer:
C.
Explanation:
This is a reaction of elimination, because the water was removed and because of it double bond is formed.
Answer:
The atoms in the first period have electrons in 1 energy level. The atoms in the second period have electrons in 2 energy levels. The atoms in the third period have electrons in 3 energy levels. The atoms in the fourth period have electrons in 4 energy levels.
B. reproduction doesn’t require mate
