Answer: 72 grams of
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number
of particles.
To calculate the number of moles, we use the equation:

Putting in the values we get:


According to stoichiometry:
1 mole of
requires 5 moles of oxygen
0.45 moles of
require=
moles of oxygen
Mass of 
72 grams of
are needed to completely burn 19.7 g 
I would say Alaska because that's where most of the subarctic climate is found.
Answer:
The atomic number is the number of the elements inside the periodic table and the mass is the weight or a number under the elements.
Explanation:
Correct me if I am wrong
Convection is when heat and cold air go around in a circle connecting the source of air, radiation is like the suns heat beam, conduction is the transfer of any source by touching and idk what biosphere and geosphere is sorry..