Physical Changes in Solid, Liquid and Gas
From the previous lesson, you have learned that when heat is added to asolid, its temperature rises. This causes the particles to vibrate
rapidly and themelting point of the solid is reached and the solid melts. When an object absorb heat, there is a corresponding increase
in temperature.
On the other hand, If heat is added, liquid particles move faster and additional heat results in the transformation of liquid into gas. At
this point, temperature is reached at which vapor pressure of a liquid equals the external pressure surrounding the liquids is called
boiling point.
Moreover, A reverse process also happens when liquid turns into a solid. In thisprocess heat is removed from liquid. The temperature
wherein a liquid solidifies is called freezing point.
Some molecules of water have enough kinetic energy to overcome the attraction of neighboring molecules and escape from the
surface of the liquidand eventually move into the air. To break away from the surface of the liquid,the molecules must have at least some
minimum kinetic energy. The processby which the molecules on the surface of a liquid break away and change into gas is called
evaporation. Usually, it is described as the process where a liquid is changed into a gas.
In this lesson, you will learn more about the physical changes matter undergo.Changes in physical state from solid to liquid and to gas or
vice versa arecommon. However, some substances change from solid to gas without passing through the liquid state. This change is
called sublimation. Examplesod substances that undergoes this kind of changes are dry ice, mothballs,toilet bowl deodorizer.
A reverse reaction in which a gas changes directly to solid without passingthrough the liquid state also happens and this is called
deposition. An example of this changes is when water vapor changes directly into frost formation.
Activity 1: Choose the letter of the best answer.
1.The following are examples of physical change except
a. Melting of ice
c. rusting of iron
b. Freezing of water
d. dissolving salt in water
2. A physical change will:
a. Create a new substance.
b. Will have an energy transference
c. Will use oxidation
d. Will change the properties of the substance
3. Condensation involves a change of state from ____ to ____
a. Liquid to solid
b. Solid to liquid
c. liquid to gas
d. gas to liquid
4. When a solid reaches the temperature of its ____, it can become a liquid.
a. Melting point
b. Boiling point
c. freezing point
d. density
5.Which of the following correctly describes how heat behaves?
a . It moves from a warmer region to a colder region
b. It does not get absorbed or released by particles of substances
c. It is gained by particles of a substance only
d. It move from a colder region
Activity 2.
Look at the diagram below and fill in the missing
letters to complete each word
Activity 3
Direction: Write the correct word that describes
the phase changes of water shown in each of the
pictures below. (Evaporation, Condensation,
Sublimation, Deposition, Freezing or Melting)
3
1
4
2
6
5
Activity 4
Essay: Condensation is the change of matter from gas to liquid. On the
other hand, sublimation is a change from solid to gas.
What happens during condensation and sublimation? Describe the
arrangement of particles during such transformation.
Activity 5
Choose the letter of the best answer. Write the chosen letter on a
separate sheet of paper.
1.Which part of the water cycle is occurring when warm, moist
air cools and begins forming clouds?
A. transpiration C. condensation
B. evaporation D. precipitation
2. Which is NOT a way that matter changes phase?
A. melting
C. evaporation
B. freezing
D. mixing
3.The drops of water that appear on the outside of a glass of cold
juice on a warm day is an example of?
A. condensation C. sublimation
B. evaporation D. precipitation
4.
Which of the following BEST explain the physical changes
in terms of the arrangement and motion of atoms and molecules
during boiling point?
A. temperature is reached at which vapor pressure of a liquid
equals the external pressure surrounding the liquids
B. A reverse reaction in which a gas changes directly to solid
without passing through the liquid state
C. substances change from solid to gas without passing through
the liquid state
D. molecules on the surface of a liquid break away and change
into gas
5. Which of the following BEST explain the physical changes in
terms of the arrangement and motion of atoms and molecules
during boiling point?
A. A reverse reaction in which a gas changes directly to solid
without passing through the liquid state
B. temperature is reached at which vapor pressure of a liquid
equals the external pressure surrounding the liquids
C. substances change from solid to gas without passing through
the liquid state
D. A reverse process also happens when liquid turns into a solid.
In this process heat is removed from liquid