The correct description for an atom of helium would be option C. An atom of helium has its valence electrons in its first energy level, it wouldn't and can't satisfy the Octet rule as it only has 2 electrons, but with 2, it has a full shell, as the first energy level can hold only 2 electrons.
Answer:
6. In order from left to right the balanced coeficcients are,
6, 1, 2, 3
8. 
9. In order from left to right the balanced coeficcients are,
1, 11, 7, 8
The heavy one because mass times force is equal to speed. The lighter one has less mass to it goes faster without as much effort. I hope that helps!
Answer:
Magnesium dichloride
HoPe ThIs HeLpS! aNd HaVe A gOoD dAy!
Yes it is for example look at Iodine and Tellurium.
Hope this helps :).