[jsmith613]

Why would melting point decreases as we descend group 1 /2 - they have more electrons?

Furthermore, why would nitrogen have a higher b.p and than O2 and O2 have a higher one that F2 - surely the stronger London Forces (due to more electrons) would mean this should be reverssed

thanks

[Nicolas88]

boiling point of nitrogen = -195.79 °C
boiling point of oxygen = -182.95 °C
boiling point of fluorine =-188.12°C

So the boiling point of oxygen is the highest then fluorine then nitrogen not like u said!

[Nicolas88]

Why would melting point decreases as we descend group 1 /2 - they have more electrons?

i think that melting point decreases as we descend group 1/2 because big atoms have bigger distance from each other nucleus than small atoms do making the bond weaker.

[jsmith613]

Why would melting point decreases as we descend group 1 /2 - they have more electrons?

i think that melting point decreases as we descend group 1/2 because big atoms have bigger distance from each other nucleus than small atoms do making the bond weaker.

oh ok.

for the previous one, none the less, why does fllourine have a lower b.p than Oxygen with greater London Forces

[Nicolas88]

Why would melting point decreases as we descend group 1 /2 - they have more electrons?

i think that melting point decreases as we descend group 1/2 because big atoms have bigger distance from each other nucleus than small atoms do making the bond weaker.

oh ok.

for the previous one, none the less, why does fllourine have a lower b.p than Oxygen with greater London Forces

because oxygen is smaller than fluorine http://boomeria.org/chemlectures/textass2/table10-9.jpg
 

[jsmith613]

Why would melting point decreases as we descend group 1 /2 - they have more electrons?

i think that melting point decreases as we descend group 1/2 because big atoms have bigger distance from each other nucleus than small atoms do making the bond weaker.

oh ok.

for the previous one, none the less, why does fllourine have a lower b.p than Oxygen with greater London Forces

because oxygen is smaller than fluorine http://boomeria.org/chemlectures/textass2/table10-9.jpg
 

but remember oxygen comes in diatomic O2 so its larger. Whats going on?

thanks

[Nicolas88]

nitrogen comes in diatomic N₂ too!

[jsmith613]

nitrogen comes in diatomic N₂ too!

OH I see that now - I can understand Oxygen and NItrogen but not oxygen and flourine

[Nicolas88]

Fluorine is a special case cause of its very high electro negativity makes the electrons more tightly bound making them less available  so intermolecular forces are smaller which makes its boiling point lower than oxygen (although fluorine has more electrons).

[Jorriss]

So....
Oxygen is larger than fluorine which helps explain that it has more significant intermolecular forces.

[PhilipCheney]

The reasons of the low melting point