Consider the densities of copper (8.96) and sulfur (2.07) , explain why 2 grams of copper takes up much less space than only 1 gram of sulfur.

Density is how "compacted" the molecules in an object are.  If copper is more dense than sulfur, then it is more "compact", meaning it takes up less physical space.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom