What observation shows us that hydrogen bonding is quite strong?

A
There is hydrogen bonding, which is due to the fast motion and collisions of the gas particles.

B
Water has a much higher boiling point compared with similar type of molecules, so we can make the assumption that there is hydrogen bonding present.

C
Water has special properties and it boils at 100 degrees Celsius, due to the strong ionic bonds present in water.

D
Heating water to the boiling point allows for bonds to strengthen together and bond with other atoms.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.

they all get energy from eating other animals, dead animals to be more precise.

hienas tends to steal pray from other animals. crows and vultures tend to eat dead animals and leftovers.

hope it ,

bioteacher101