How is classification is used at school?

Which best describes the nucleus of an atom a. it is where all of the particle s of the atom are located b. it is the negatively charged part of the atom c. it is where the electrons and the protons are located d. it is the part of the atom with the greatest mass

What are some natural processes that represent physical and chemical changes?

How do the sperm cells get from the stigma to the ovules?