As the air molecules move through the valve they have friction as they hit the walls, and its this friction that causes it to heat up.
The elements in each group have the same number of electrons in the outer orbital. Or also called valence electrons. Khan academy has a great video online explaining why this happens. (It only happens for main group elements). Here is a link (sorry you can’t click it in Brainly) https://www.khanacademy.org/science/chemistry/periodic-table/copy-of-periodic-table-of-elements/v/periodic-table-valence-electrons. Feel free to message me for a better explanation, I would explain now but I’m not sure how much you know about this. If you know how to write an electron configuration you can see how all the electron configurations for the same group (not the transitional metals only the main groups) have the same number of valence electrons. I hope that helped, sorry I was vague about the explanation :)
Any substance that accept a proton by definition is considered to be BRONSTED LOWRY BASE.
Bronsted Lowry defined acid and base on the basis of donating or accepting protons. In the Bronsted Lowry classification of acid and base, an acid is defined as a substance which donate proton while a base is defined as a substance which accept proton.
i may be wrong but Use the normal boiling points: propane, C3H8, –42.1˚C; butane, C4H10, –0.5˚C; pentane, C5H12, 36.1˚C; hexane, C6H14, 68.7˚C; heptane, C7H16, 98.4˚C; to estimate the normal boiling point of octane, C8H18.
Answer:
They are Weaker than a chemical
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corrected by the one in the comment section