A
The number of electrons/protons is the one that determines the atomic number of an element.
Answer:
Mass = 279.23 g
Explanation:
Given data:
Number of moles of Fe₂O₃ = 3 mol
Number of moles of Al = 5 mol
Maximum amount of iron produced by reaction = ?
Solution:
Chemical equation:
Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
Now we will compare the moles of iron with Al and iron oxide.
Fe₂O₃ : Fe
1 : 2
3 : 2×3 = 6 mol
Al : Fe
2 : 2
5 : 5 mol
The number of moles of iron produced by Al are less so Al is limiting reacting and it will limit the amount of iron so maximum number of iron produced are 5 moles.
Mass of iron:
Mass = number of moles × molar mass
Mass = 5 mol × 55.845 g/mol
Mass = 279.23 g
There are several ways to give an object potential energy. One can move the object against the force of gravity to increase. One can also stretch an object out or put pressure on it.
They discovered that *elements* show increase in atomic numbers across the period.
