Ionic bonds are formed due to tendency of a metal to donate an electron and tendency of non metal to gain an electron.
6.023*1023 He atoms=1 mole He
1.23×1024 helium atoms=1.23×1024/6.023*1023 =2.042 mole He
one mole He=4.0 gm
2.042 mole He=2.042*4.0=8.168 gm
answer in grams of Helium is 8.168 gm
4
Numbers above zero are significant, as well as any zeros that appear in between two non-zero numbers.
27 + (35,5 + 2* 16) * 3 = 229.5 g/mol
the second statement is the correct one quarks are needed to balance charges in all subatomic particles such as neutrons, protons and electrons