It has many different uses like being used to make the tube of a vacuum cleaner and also can be used to make oil in space crafts.
Answer: the 1st one is B, 2 is A, 3 is A, 4 is a or D for this one, 5 is c, 6 is b, 7 is b, 8 is d, 9 is a, 10 is b those are my best guess and if that did work I'm sorry I didn't help you and take care also have a great day.
Answer:
NH3 < NF3 < BCl3
Explanation:
The vapour pressure of a substance has something to do with the nature of intermolecular forces between its molecules. If the molecules of a substance are held together by strong intermolecular forces, the substance will display a low vapour pressure at a given temperature and vice versa.
Ammonia has the lowest vapour pressure because of strong intermolecular hydrogen bonds that hold its molecules together.
When iron loses the 2 4s electrons, it attains a valency of +2. Sometimes, iron will also lose one of the paired electrons from 3d orbital, leaving the entire 3d orbital filled with unpaired electrons (which provides a more stable configuration). In this case, its valency will be +3.