Answer:
Manganese: Mn
Explanation:
The elestron configuration would show this is 25 electrons
Atomic number : 25
this electron configuration ends in 
half of the d subshell which is 10
Answer: 13.9 g of
will be produced from the given mass of oxygen
Explanation:
To calculate the moles :

The balanced chemical reaction is:
According to stoichiometry :
7 moles of
produce = 6 moles of 
Thus 0.900 moles of
will produce =
of 
Mass of 
Thus 13.9 g of
will be produced from the given mass of oxygen
Answer:
6 moles of Cl2
Explanation:
First, the equation has to be balanced, which makes it 4 FeCl3 + 3 O2 --> 2 Fe2O3 + 6 Cl2
Using this information, we can see that one mole of O2 will not be present in the reaction. Since four moles of FeCl3 are needed to react in the equation, which would produce six moles of Cl2, and only four moles of FeCl3 are present, six moles of Cl2 would be produced.
Moles = mass / molar mass
molar mass of O2 is 32
therefore moles = 72/32
= 2.25 moles