Answer:
Van der waal's force of attraction
Explanation:
Van der waal's force of attraction
Forces of Van der Waals involve attraction and repulsion among atoms, particles, and surfaces as well as many other intermolecular forces. These vary from covalent and ionic bonding in that they are caused by similarities in surrounding particle fluctuating polarizations (a result of quantum dynamics).
He answer is 42 because you carry the one
"The other halogens are not as electronegative and so other hydrogen halides cannot form hydrogen bonds between molecules. Only London Forces are formed. - Therefore more energy is required to break the intermolecular forces in HF than the other hydrogen halides and so it has a higher boiling point."
not a hack link, just stating where i got your answer from! -
https://www.mytutor.co.uk/answers/17558/A-Level/Chemistry/Explain-the-unusually-high-boiling-point-of-HF/
<span>A. Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.
</span>Which of the following could be said about ecological footprints? <u /> <u>Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.</u><u />
NOT:
b. Ecological footprints can't be used to determine carrying capacity.
C. Ecological footprints don't take into account resources needed to absorb and manage wastes.
<span>D. The average ecological footprints for various countries are nearly identical.</span>
