First we will calculate the number of moles of Iron:

, where n is the number of moles, m is the mass of iron in the reaction and M is the Atomic weight.

moles of Iron.
The same number of moles of Oxygen will take part in the reaction.
So

where 32 is the Atomical Weight of Oxygen (16 x 2).
=>

g
Answer:
Velocity = Distance Covered÷Time Taken
Velocity = 4000÷8
V = 500
Answer:
Potassium (K) [First element in period 4]
We know it’s C because of what it says in the text
She ran at either 5m/s
Or 11.185 miles/hr
Explanation:
Aight well if she did 100m in 20s then that’s 5m/s which would also be 11.185M/h
m = meters
M = miles
Hope this helps!