2 molecules of N2, because the hydrogen is the limiting reactant, leaving there to be more N (4 molecules) so those 4 molecules create 2 N2 molecules.
Answer:
The magnesium reacted with the oxygen in the air.
Explanation:
For argument’s sake, let’s say that the mass of magnesium oxide was 3 g and that of the oxide was 5 g.
The reaction was
magnesium + oxygen ⟶ magnesium oxide
Mass: 3 g 5 g
Mass of oxygen = 5 g – 3 g = 2 g
The 3 g of magnesium must have combined with 2 g of oxygen to form 5 g of magnesium oxide.
In ionic bonding, atoms SHARE ELECTRONS
Density = mass/volume
so rearranged mass = volume x density
mass = 8.920 x 45 = 401.4g
rearrange (there are 1000grams in 1kg)
volume = mass/density
volume = 1000/8.920
volume = 112.1076233cm3
1) D = 13.6 g / mL
2)ethyl alcohol weighs 158g
3)ρ
_copper = 8.9 g 
Explanation:
1)
D = m / V
=306.0 g / 22.5 mL
D= 13.6 g / mL
2)
density = mass / volume
mass = density × volume
=0.789g /ml × 200.0 ml
M=158g
Ethyl alcohol weighs 158g
3)
ρ (density) = Mass / Volume
ρ
_copper = 1896 g / 8.4cm × 5.5cm × 4.6cm
= 1896g / 212.5 
ρ
_copper=8.9 g 