2. what is the boiling point of the substance?
3. what is the melting point of the substance?
4. what letter represents the range where the solid is being warmed?
5. what letter represents the range where the liquid is being warmed?
6. what letter represents the range where the vapor is being warmed?
9. what letters(s) shows a change in potential energy?
10. what letter(s) shows a change in kinetic energy?
and 12. what letter represents crystallization?
i've attached the file so you can see the freezing and boiling point graph.

2.it is 15°C.

3. 5°C

4. a

5. c

6. e

9. b & d

10. a, c & e

12. a

Explanation:

Hello,

To analyze the graphic you have to remember the three states of matter, solid, liquid and gas.

In energy terms, solid is less energetic than liquid, and liquid is less energetic than gas.

If you look at the image attached, you can observe that all the three states are very differentiated from each other. I used red numbers to mark these states:

1 = solid state

2 = liquid state

3 = gas state

This is related to the sense of the increase of energy (follow the arrow on the horizontal axis).

Then, look the letters a, c, and e, these letters are showing the same that the numbers in red: the three states of the substance.

The letters b, and d are pointing the transitions states of solid and liquid, where even when the energy increases, the state doesn’t change, it means, still liquid, and still solid to these temperatures.

With this in mind, you can read the graphic and answer the questions:

2. The boiling point is the transition temperature from liquid to gas, in the graphic is c to e, it is 15°C.

3. The melting point is the transformation from solid to liquid, in the graphic, it means c to a, it is 5°C

4. solid-state warming has to be represented by letter a, look the temperature is rising, to the next state. It's not letter b, because temperature it's not changing.

5. Like the question above, the warming is when temperature increases, it is letter c

6. e.

9. The letters who show a change in potential energy are, the letters above the horizontal line of the graphic: b and d.

10. The letters who shows a change in kinetic energy are the letters who are related to changes in temperature. these are: a, c and e.

12. crystallization is a process of solidification of a substance, this has to be related to letter a, also, the crystallization is the process where the substance decay to the less energetic state that is also the more stable.

there is none because earth is stationary and flat.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.