Beryllium is a chemical element with symbol Be and atomic number 4. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays.
Answer:
The electrons that occupy the outermost shell of an atom are called valence electrons. Valence electrons are important because they determine how an atom will react. By writing an electron configuration, you'll be able to see how many electrons occupy the highest energy level .
C.
Water is polar because one side of the molecule is positive and the other is negative.
Here are the resonance contributors I found.