Answer: (a) There are 0.428 moles present in 12 g of 
molecule.
(b) There are 2 moles present in 
particles of oxygen.
Explanation:
(a). The mass of nitrogen molecule is given as 12 g.
As the molar mass of is 28 g/mol so its number of moles are calculated as follows.
So, there are 0.428 moles present in 12 g of molecule.
(b). According to the mole concept, 1 mole of every substance contains 
atoms.
Therefore, moles present in particles are calculated as follows.
So, there are 2 moles present in particles of oxygen.
Answer: See below
Explanation:
1. a) 0.15 moles calcium carbonate (15g/100g/mole)
b) 0.15 moles CaO (molar ratio of CaO to CaCO3 is 1:1)
c) 8.4 grams CaO (0.15 moles)*(56 grams/mole)
2. a) 0.274 moles Na2O (17g/62 grams/mole)
b) 46.6 grams NaNO3 (2 moles NaNO3/1 mole Na2O)*(0.274 moles Na2O)*(85 g/mole NaNO3)
Answer:
electron, proton, nucleus, atom, molecule teacher
I am pretty sure it is 4.002602
1 atom Mg, 2 atoms O and 2 atoms H.
1 + 2 + 2 = 5, so correct answer is C
