What is the strongest evidence for hydrogen
bonding?
1. Hydrogen has an extremely low electronegativity.
2. The boiling points of NH3, H2O, and HF
are abnormally high compared with the rest
of the hydrides in their respective periods.
3. Hydrogen can be considered either a
metal or nonmetal.
4. Hydrogen is able to accept or donate electrons, so it is the most versatile atom in the
periodic chart.

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt