Carbon dioxide (CO2)
Argon (Ar)
Hydrogen (H)
Helium (He)
<span>This example represents the challenge of survival of the fittest. In this situation, the trees have a distinct advantage due to their above average height. This puts them in the best position to gain the resources that they need to survive, most notably, the sun. The smaller plants, however, do not have this advantage, and lose out to the trees.</span>
Answer:
Sr is the more metallic element
Bi is the more metallic element
O is the more metallic element
As is the more metallic element
Explanation:
One thing should be clear; metallic character increases down the group but decreases across the period.
Hence, as we move across the period, elements become less metallic. As we move down the group elements become more metallic.
This is the basis upon which decisions were made about the metallic character of each of the elements listed above.
Answer: 
is the limiting reagent
Explanation:
To calculate the moles :
The balanced chemical reaction is :
According to stoichiometry :
1 moles of require = 2 moles of 
Thus 0.625 moles of will require=
of
Thus is the limiting reagent as it limits the formation of product and is the excess reagent as it is present more than the required amount.
