Answer:
2
Explanation:
The atom shown in the image has 2 core electrons.
Electrons are the negatively charged particles within an atom. Therefore the total number of electrons surrounding the nucleus in the given specie is 7.
So;
We have 2 core electrons
And 5 valence electrons
The core electrons are the inner orbital electrons.
The valence electrons are the outermost electrons.
In nuclear fission heavier elements are split to make lighter elements whilst releasing energy. An atom, its nucleus to be more specific, is bombarded with neutrons. The nucleus becomes unstable and it starts to split/decay. It creates the fusion products. Neutrons and lighter elements are released; the neutrons from the nuclei of the atom(s) being split.
The answer is D because most stained glass is held together with lead. The process of this is called leading.
Koalas are not crusty, but their fur is very coarse, like wool.
Hope this helps.