mesozoic era - age of the dinosaurs
end of the paleozoic era - most of earth a desert
end of the mesozoic era - a layer of iridium deposited all over earth
I don’t see a 2+. If you’re talking about the number next to your cursor, it’s a 23.
Chlorine needs only one electron to complete valance shell and Na needs give up electron be get down to last complete valence shell. so Na+Cl
The hydrogen bonds is an intermolecular force.
This is, it is an atracction among molecules, which trends to keep the molecules close one to each other quite strongly.
Vaporization is the pass from liquid, where the molecules are pretty close one to each other, to gas, where the molecules are more distant from each other. To reach that separation of the molecules, the strong hydrogen bonds must be overcome, which means a higher energy requirement than in similar compounds without hydrogen bonds.
That is reflected in high values for the enthalpy of vaporization in the compounds with hydrogen bonds (like hydrogen halides).
So, that leads to the option D. of the list of answers. enthalpy heat of vaporization gives the best indication of the relative strenght of hydrogen bonds.