B3+ is isoelectronic with helium.
Isoelectronicity is the phenomenon whereby two or more molecular entities have the same number of electrons or similar electronic configuration regardless of the nature of the elements that are involved.
In the question given above, helium and B3+ have the same number of electrons. Helium has two electrons. Boron has five electrons but it has given away three of the electrons [that is why it has a charge of +3] and it now has only two left.
Answer: option a and d
Explanation:
Option A- Benzene undergoes substitution reaction
Example : benzene reacts with chlorine to form chlorobenzene, in the presence of Iron
(iii) chloride as a catalyst
C6H6 + Cl2 ---> C6H5Cl + HCl
Option D- Benzene also undergoes addition reaction
Example: benzene reacts with hydrogen , in the presence of nickel as a catalyst to form
cyclohexane
C6H6 + 3H2 ---> C6H12
Reasons why Option B isn't the answer
Although benzeme has degree of unsaturation but it's not five degree of unsaturation.
Benzene has 6 carbon atoms and 4 degrees of unsaturation (1 ring and 3 double
bonds).
If you work backwards and double the degrees of unsaturation you have 8 degrees of
unsaturation instead of 5.
Option C - Benzene isn't a saturated hydrocarbon
for it to be balanced in this case would be " <em>4</em> C6H6 + <em>6</em> CI2 = <em>3</em> C6H5CI + <em>9</em> HCI" therefore it's be a <u>Double Replacement</u>
Answer: electron on the shell of the atom
Explanation: that what I trying to remember
