What is the definition of isotope? isomers? ions? examples? Definition, examples, for the ions, positively charged? Negatively charged?

Question 23. Classify each element as a metal, nonmetal, or metalloid.  barium. 1.Metal 2.nonmetal 3.metalloid

What needs to be true in order for an atom to have a neutral charge

16. Average atomic mass is different from mass number because... A. the average atomic mass describes the mass number of a single atom, but mass number describes the average of all exact masses among isotopes of an element. B. mass number describes the approximate mass of the nucleus of a single atom, but average atomic mass describes the weighted average of all the exact masses among isotopes of an element. C. mass number describes the exact mass of a single atom, but average atomic mass describes the average of all mass numbers. O D. mass number describes the approximate mass of the nucleus of a single atom, but average atomic mass describes the largest mass among isotopes of an element.