Answer: 3.0 moles of water 
are needed to react with a mole of 3.0 of Na
Explanation:
The balanced chemical reaction of sodium with water is as follows:
According to stoichiometry:
2 moles of sodium 
reacts with = 2 moles of water
Thus 3.0 moles of sodium reacts with = 
moles of water
3.0 moles of water are needed to react with a mole of 3.0 of Na
Just add up all the "exponents" and you'll get 25 which is Manganese or Mn on the periodic table!
Answer:
Group 1
because they have just one valance electron, group 1 elements are very reactiv.
Answer:
validity is the extent to which a test measures what it claims to measure. It is vital for a test to be valid in order for the results to be accurately applied and interpreted.
Explanation:
Validity is important because it can help determine what types of tests to use, and help to make sure researchers are using methods that are not only ethical, and cost-effective, but also a method that truly measures the idea or constructs in question.
