Answer:
According to the Environmental Paper Network's Paper Calculator, it takes about 32 million BTUs of energy to produce 1 ton of virgin paper fiber. To produce 1 ton of recycled paper, it takes about 22 million BTUs.
so the answer could be it takes less Btu to manufacture recycled products than new ones
Answer:
Convection.
Explanation:
Why? This transfer of heat energy away from the ground by the vertical movement of air is called "free convection" or "natural convection." A hot air balloon rises because warmer air is less dense than cool air. (plz brainlyest)
Answer:
The number of moles =

The number of molecules =

Explanation:
Volume of the sphere is given by :

here, r = radius of the sphere


Radius = 3 mm
r = 3 mm
1 mm = 0.01 dm (1 millimeter = 0.001 decimeter)
3 mm = 3 x 0.01 dm = 0.03 dm
r = 0.03 dm
<em>("volume must be in dm^3 , this is the reason radius is changed into dm"</em>
<em>"this is done because 1 dm^3 = 1 liter and concentration is always measured in liters")</em>



(1 L = 1 dm3)
Now, concentration "C"=
The concentration is given by the formula :

This is also written as,

moles
One mole of the substance contain "Na"(= Avogadro number of molecules)
So, "n" mole of substance contain =( n x Na )

Molecules =

molecules
This problem is providing the chemical reaction whereby barium nitride reacts with water to produce barium hydroxide and ammonia, so the number of moles of barium nitride are required in order to produce 8.3 moles of ammonia. It asks for us to evaluate the student's setup, so we conclude the answer is C. "1 mol of NH3 should be replaced with 2 mol of NH3", according to:
<h3>Mole ratios:</h3>
In chemistry, stoichiometric calculations are used to figure out the moles or mass of a substance, given information about another one in the reaction. In this case, for the given chemical equation:

We evidence a 1:2 mole ratio of barium nitride to ammonia, for that reason, the student's setup:

Is incorrect, because the ammonia must be accompanied by a 2 rather than the 1 it is given there:

Thereby, the correct answer is C. "1 mol of NH3 should be replaced with 2 mol of NH3"
Learn more about mole ratios: brainly.com/question/15288923