JAMB Past Questions and Answers - Page 1249

Once you figure out the electron configuration, you fill up the corresponding orbitals with electrons, any left with one is considered unpaired. Since 1s can only hold 2 electrons, and P has 15, that's obviously filled and has no unpaired electrons. The same is for 2s which holds 2, 2p which holds 6, 3s which holds 2.

However 3p can hold 6 electrons and in order for that to be filled up you would need to have an element of 18 electrons. So you fill up as much as you can in 3p by first adding 1 electron to each energy level. 3p has 3 energy levels and there are only 3 electrons left to distribute, so each of those energy levels only gets 1, because you have to fill them all with one before you can start adding a second.

So since you are only able to fill one electron in each of the three energy levels of the 3p orbital, that leaves the orbital open for 1 more electron in each of its energy levels. So there are 3 unpaired electrons in P.

In this method of stock valuation, the average unit cost is calculated by multiplying the total of the unit costs by the number of receiving. 

The closing stock using simple average =

(33 ÷ 3) x 1500 = 16500

The following factors increase a reaction rate
- Increase in concentration of reactants
- Increase in temperature
- Addition of catalyst
- Increase in the surface area of reactant(s)

FIFO means first in first out. This method assumes that the oldest products in a company’s inventory have been sold first. The costs paid for those oldest products are the ones used in the calculation.

From the table above, value of closing stock using FIFO = 

Total closing stock = 1500

previous stock bought at N12 = 500 units

Last stock bought at N11 = 1000 units

12 x 500 + (11 x 1000) = 17,000

Gibb's free energy is the fraction of the total energy of a system that accounts for how much useful work can be done in a system.