Answer:
14.68 moles of He
Explanation:
To do this, just remember Avogadro's Constant or Avogadro's number. This constant tells us how many units ( in this case atoms) there are in a mole of ANY type of substance.
Avogadro's constant is 6.022140857 × 10²³ units per mole.
Now that we know how many atoms there are in 1 mole, we can use this as our conversion factor.
8.84 x 10²⁴ atoms of He → moles of He

So the answer would be:
14.68 moles of He
Answer:
they must have same atomic number and different atomic mass
Global Warming has been increased by living organisms like animals and humans by many ways:
1) We burn fossil fuels, which is very bad for our Environment's health
2) Animals like cows & buffalo produces a lot of methane which causes Global Warming.
3) Animals cut a lot of trees for their products, so increase the amount of Carbon dioxide in the atmosphere, thus increases Global Warming.
4) We don't minimize our dependence on Non-renewable source of energy which 'causes a lot of pollution in the environment
Hope this helps!
Answer:
Reverse the
reaction
Explanation:
Reactions:

Overall:

As can be seen, in the overall reaction we have
in the reactants like in the second reaction and
in the products. The
is in the first reaction but as a reactant so we need to reverse that reaction:

Combining:


Scientists make hypothesis in order to make an educated guess on the outcome of the experiment.