Rarely they can't with just sight. Certain tests or experiments should take place
Answer: D. 19.9 g hydrogen remains.
Explanation:
To calculate the moles, we use the equation:
a) moles of
b) moles of
According to stoichiometry :
1 mole of
require 1 mole of
Thus 0.0787 moles of
require=
of
Thus
is the limiting reagent as it limits the formation of product and
acts as the excess reagent. (10.0-0.0787)= 9.92 moles of
are left unreacted.
Mass of
Thus 19.9 g of
remains unreacted.
It’s c I believe because it says 209 years to complete an orbit so hint yourself ?.....
Answer:
D because excited electrons fall back.....