Since the total amount of valence electrons is 3, it is in group 13 in the periodic table..therefore, it is specified as Boron.✅
I don't know this article, but I do know some major changes: first, the change from the plum pudding model (no nucleus, just electrons) to the gold foil experiment, which had Rutherford shoot alpha particles at a sheet of gold only to find them rebounding, proving the existence of a positively charged mass, i.e a nucleus, in the atom. However, this changed again when Bohr realized that the negatively charged electrons should be attracted to the positively charged center, so that there must be something else inside the nucleus.
Answer:
0.677 moles
Explanation:
Take the atomic mass of K = 39.1, O =16.0, P = 31.0
no. of moles = mass / molar mass
no. of moles of K3PO4 used = 4.79 / (39.1x3 + 31 + 16x4)
= 0.02256 mol
From the equation, the mole ratio of KOH : K3PO4 = 3 :1,
meaning every 3 moles of KOH used, produces 1 mole of K3PO4.
So, using this ratio, let the no. of moles of KOH required to be y.

y = 0.02256 x3
y = 0.0677 mol
If you don't find exactly 0.677 moles as one of the options, go for the closest one. A very slight error may occur because of taking different significant figures of atomic masses when calculating.
Answer: Partial pressure of
at a depth of 132 ft below sea level is 2964 mm Hg.
Explanation:
It is known that 1 atm = 760 mm Hg.
Also, 
where,
= partial pressure of 
P = atmospheric pressure
= mole fraction of 
Putting the given values into the above formula as follows.


= 0.780
Now, at a depth of 132 ft below the surface of the water where pressure is 5.0 atm. So, partial pressure of
is as follows.

= 
= 2964 mm Hg
Therefore, we can conclude that partial pressure of
at a depth of 132 ft below sea level is 2964 mm Hg.