Lesson 1.3: Properties and Changes of Matter
Learning Objectives
At the end of the lesson, you (student) should be able to:
1. Distinguish between physical and chemical properties and give examples.
2. Distinguish between extensive and intensive properties and give examples.
3. Differentiate physical from chemical change.
Learning Time (Acquire New Knowledge)
This time I want you to proceed to this part wherein, you will learn more about the different
properties and behaviors of matter. As you move learning the lesson, I want you to check whether
your answer is correct based on the question presented.
Substances are identified by their properties as well as by their composition. Color,
melting point, and boiling point are physical properties. A physical property can be measured and
observed without changing the composition or identity of a substance. For example, we can
measure the melting point of ice by heating a block of ice and recording the temperature at which
the ice is converted to water.
Water differs from ice only in appearance, not in composition, so this is a physical change;
we can freeze the water to recover the original ice. Therefore, the melting point of a substance is
a physical property. Similarly, when we say that helium gas is lighter than air, we refer to physical
property. On the other hand, the statement "Hydrogen gas burns in oxygen gas to form water"
describes a chemical property of hydrogen, because to observe this property, we must carry out
a chemical change, in this case, burning. After the change, the original chemical substance, the
hydrogen gas, will have vanished, and all that will be left is a different chemical substance—water.
We cannot recover the hydrogen from the water by means of a physical change, such as boiling
or freezing.
