A20.0g sample of mercury(ii) oxide (hgo, m = 216.6) is heated strongly, causing it to decompose to metallic hg and o2 gas. what volume of o2 gas is produced( measured at stp)
(a) 1.03l (b) 2.07l (c) 4.14l (d) 14.0l
when 30.0 ml of 0.10 m agno3 is added to 30.0 ml of 0.10 m nacl, aqueous nano3 and solid agcl are formed. how much solid agcl is produced?
(a) 0.003 mol (b) 0.0060 (c) 0.030 mol (d) 0.060

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.