Answer:
1. First one is true : as per periodic table down the group , the elements has increasing order of shell & with that the London dispersion forces brings the inter-molecules close together and bromine converted into liquid .
2. second one is False because carbon-carbon bonds are not weak bonds they form mutual covalent bonds which are stronger bonds and cannot be easily disrupted .
3. A single carbon atom has the valency of 4 so it can be bonded with four hydrogen atom at the same time .
Explanation:
i may be wrong but Use the normal boiling points: propane, C3H8, –42.1˚C; butane, C4H10, –0.5˚C; pentane, C5H12, 36.1˚C; hexane, C6H14, 68.7˚C; heptane, C7H16, 98.4˚C; to estimate the normal boiling point of octane, C8H18.
There are 18 protons and electrons and 22 neutrons in the atom