Answer:
797.34 moles of H₂
Explanation:
From the question given above, the following data were obtained:
Number of molecules of H₂ = 4.8×10²⁶ molecules
Number of mole of H₂ =?
From Avogadro's hypothesis,
1 mole of H₂ = 6.02×10²³ molecules
With the above information, we can determine the number of mole of H₂ that contains 4.8×10²⁶ molecules as follow:
6.02×10²³ molecules = 1 mole of H₂
Therefore,
4.8×10²⁶ molecules = 4.8×10²⁶ / 6.02×10²³
4.8×10²⁶ molecules = 797.34 moles
Thus, 797.34 moles of H₂ contains 4.8×10²⁶ molecules.
Answer:
Number of Protons, 28. Number of Neutrons, 31. Number of Electrons, 28
Explanation:
N/A
The slight error has been to use the prefix mono to name monocarbon.The compound she is most likely naming is:

.
As you see, the chemical formula has 1 atom of C, which is likely why she named it mono, and 4 atoms of Br.
The right name is carbon monobromide, i.e. you have to supress the prefix mono, as per IUPAC rules.
Number of atoms in 1.4 mol of Phosphorus trifluoride (PF₃) : 8.428 x 10²³
<h3>Further explanation </h3>
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
1.4 mol of Phosphorus trifluoride (PF₃), number of atoms :

I think it’s chemical reactivity