What volume of O2 at NTP is generated from 7.84 g of
FeSO, (NH4)2SO4.6H2O?

1.12 g

Explanation:Molar mass of compound ​FeSO4(NH4)2SO4.6H2O = 392.14 g mol-1

Number of moles of compound in 7.84g sample = 7.84 g/ 392.14 g mol-1

                                                                       = 0.02 mole

1 mole of sample contain 1 mole of Fe

So, 0.02 mole of sample would contain 0.02 moles of Fe.

Mass of Fe equivalent to 0.02 mole = 0.02 mol x molar mass of Fe

                                                    = 0.02 mol x 55.84 g mol-1

                                                   = 1.12 g

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.