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:
Decomposition
Explanation:
If we look at the process;
2 NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g)
We can see that NaHCO3 was broken down into Na2CO3, H2O and CO2.
The breakdown of one compound to yield other chemical compounds is known as decomposition.
Hence the NaHCO3 was decomposed in the process above.
Plants need oxygen to survive.
Answer: Oxygen.
Explanation: The -ate is used for the ion that has the largest number of Oxygen atoms. The -ite would be used for the ion with the smaller amount of oxygen atoms.