Because it may not contain Hydrogen or Oxygen
The charge of a nucleus is neutral, meaning it’s zero
the positive charges of an atom equal the negative charges so the atom has a neutral charge
<span>Many life forms consist of a single cell. As well as simple bacteria, there are more complex organisms, known as protoctists. Unlike bacteria, they have complex internal structures, such as nuclei containing organized strands of genetic material called chromosomes. Most are single-celled, but some form colonies, with each cell usually remaining self-sufficient.</span>
