Answer:
H-F is a polar covalent molecule in which dipole-dipole interactions exists
Explanation:
Sodium and potassium are in the same group on the periodic table because they both have similar number of valence electrons (1 electron) in their shells
Na = 2,8,1
K = 2,8,8,1
Answer:
Liquid and gas
Explanation:
Liquid and gas are the phases of matter that take the shape of container.
This is very simple to imagine, if we have a piece of rock and we put it in a container, it will not take the shape of container as it already has a definite shape and volume. Liquid when put in a container takes the shape of container but varies in volume as per the container.
However, the gas phases is the phase of matter that perfectly takes the shape of container and occupies all the volume of container as well.
If we recall Dalton's Law of Partial Pressures we can see that the pressure exerted by the gas components in a container is same like the pressure exerted by the gas alone. These partial pressures of the component of gas combine in such a way that they exert total pressure equal to the constituents' pressure on the container. This way gases occupy all the volume of a container and take the shape of a container they're placed in.
Hope it help!
Mixtures are combinations of materials that can be separated by in most cases time. For instance, oil and water is a mixture. You can tell this by placing the two chemicals in a container and shaking them. They will mix and look like one substance, however, they will separate into the two liquids after some time is given. Assuming that "pure substance" is a solution, a substance is similar to a mixture, but the materials used in the solution are not separable. Over time the materials in the containing will not separate. I believe this is the answer you are looking for.
Answer:
(a) The final pressure of the sample becomes one-fourth of the original pressure.
(b) The pressure of the sample remains unchanged.
(c) The final pressure of the sample becomes four times of the original pressure.
Explanation:
(a)

The volume of sample doubled and kelvin temperature halved.



Therefore, the final pressure of the sample becomes one-fourth of the original pressure.
(b)
Volume and temperature of sample doubled.



Therefore, the pressure of the sample unchanged.
(c)
Volume of sample halved and temperature double.



Therefore, the pressure of the sample becomes four times of the original pressure.