Answer:
= 3.01× 
molecules.
Explanation:
1 mole of 
- 98g
? moles of - 49g
= 49 ÷ 98 = 0.5 moles of O2 in 49g.
But 1 mole of any substance = 6.023 × molecules
∴ 0.5 moles = 0.5 × 6.023 × molecules
= 3.01× molecules.
Answer: 5.84x10^4
Explanation: You start with (9.00x10^26 atoms)x(1 mol/ 6.022x10^23)x(39.10 g/1 mol)
It is possible because the electrons in the energy level furthest from the nucleus delocalise, this leaves behind positively charged metal ions which are attracted to the negatively charged electrons that now move around the lattice freely
