Answer:
15
Explanation:
the atomic number is the number above the symbol. the number below is the atomic mass.
Answer:
these differentiate as a result of signaling mechanisms. ... The daughter cells divides and after each division it becomes more specialized. When it reaches a mature cell type downstream (for example, becomes a red blood cell) it will no longer divide.
Introduced species can harm our planet because in some regions of the world we are not prepared for their type of species, which can all in all cause damage.