Which of the following best identifies a theme of the text?

Study this image which statement best describes the rock shown check all that apply

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

Some substances but not other can cross the (blank) membrane of a cell