How many grams do 6 × 1020 atoms of helium weigh? answer in units of g.

1.2204504e-18   i think   hope this helped 

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

7is b8 is d9 is c10 is a11 is d