A block of concrete has a mass of 5100 g and a volume of 2500 cm3 . Calculate the density.

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

Any vitamins or supplements can be obtained without prescription and are widely used as alternative from western medications. most supplements are not valued by the fda or any other drug and food agencies.