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States of matter and the kinetic molecular theory

Exercise 3.1

Give one word or term for each of the following descriptions.

  1. The change in phase from a solid to a gas.

  2. The change in phase from liquid to gas.

sublimation and evaporation

Water has a boiling point of 100℃

  1. Define boiling point.

  2. What change in phase takes place when a liquid reaches its boiling point?

  1. see definition

  2. liquid to gas

Describe a solid in terms of the kinetic molecular theory.

Solution not yet available.

Refer to the table below which gives the melting and boiling points of a number of elements and then answer the questions that follow. (Data from http://www.chemicalelements.com)


Melting point (℃)

Boiling point (℃)


\(\text{1 083}\)

\(\text{2 567}\)



\(\text{1 107}\)





\(\text{3 500}\)

\(\text{4 827}\)







  1. What state of matter (i.e. solid, liquid or gas) will each of these elements be in at room temperature (25℃)?

  2. Which of these elements has the strongest forces between its atoms? Give a reason for your answer.

  3. Which of these elements has the weakest forces between its atoms? Give a reason for your answer.

  1. solid, solid, gas, solid, gas, solid

  2. carbon

  3. helium

Complete the following submicroscopic diagrams to show what magnesium will look like in the solid, liquid and gas phase.

Solution not yet available