It is supposed to protect the cell from it's surroundings, or from the outside.
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 is: (4) emits energy as it moves to a lower energy state.
Atom emits a characteristic set of discrete wavelengths, according to its electronic energy levels.
Emission spectrum of a chemical element is the spectrum of frequencies emitted due to an atom making a transition from a high energy state to a lower energy state.
Each transition has a specific energy difference.
Each element's emission spectrum is unique.
If its one part magnesium and two parts hydroxide id say 88g of magnesium
I am going to say C. it has to do with the angles
