The document discusses the concepts of evaporation and vaporization, explaining that while both processes involve the transition from liquid or solid to gas, they occur under different conditions and at different rates. Evaporation is a type of vaporization that occurs at temperatures below boiling points and is a slower process influenced by factors such as temperature, surface area, humidity, and wind speed. The document concludes by highlighting the main differences between the two processes on a molecular level and emphasizes that both are physical changes with no alteration in chemical composition.

1. www.takshilalearning.com call 8800999284
CBSE Online Class 9 Science – Evaporation Vs Vaporization
Evaporation and vaporization are two commonly occurring processes in our
nature. These two processes are the primary reasons behind rainfall. In fact,
evaporation is a type of vaporization that occurs in our surroundings.
Although these two words seem to have similar meanings, many differences still
exist. Therefore, we will understand what the two terms mean and how they
differ from one another.
Before we proceed, we encourage you to have a basic understanding of the
states of matter. To get an understanding, check out our blog.
What is vaporization?
Have you ever seen a boiling pot of water left for far too long on the stove? I
definitely have every time I make Maggi for myself. And every time, half the
water just magically vanishes!
So this magical process is called vaporization – It is the process by which intense
heat is used to transfer a substance from a solid or liquid state to a gaseous
state. It should be noted that these changes occur from one state of matter to
another without any change in the chemical composition.
Vaporization can be of three types –
Boiling – During the boiling process, the transition from the liquid phase to the
gaseous phase occurs at or above the boiling temperature. This process leads to
the formation of vapour as bubbles of high-temperature water below the
surface of the liquid. Our initial example of water on the stove involves the
process of boiling.
Sublimation – The sublimation process of vaporization directly transitions a solid
to a gas without passing through the liquid phase.
Evaporation – Similar to boiling, evaporation involves the transition of a solid or
liquid to gas. However, this transition occurs at temperatures lower than the
boiling temperature. Now let’s learn more about this!
What is the evaporation process?
As stated above, the evaporation process is a type of vaporization wherein a
solid or liquid transforms into gas and this process takes place below the boiling

2. www.takshilalearning.com call 8800999284
point at a given pressure. Evaporation is a slow process that requires massive
energy.
A very prominent example of the evaporation process is our planet’s water
cycle. The intense energy of the Sun provides heat to the planet’s various water
bodies, such as the oceans, seas, and rivers. Further, water from other sources,
such as moisture in soil and plants, also get heat from the Sun. As the Sun
provides energy to such water sources, liquid molecules of water evaporate to
form clouds. These clouds release water back to Earth in the form of rain.
This example tells us that evaporation is the most common type of vaporization
in nature as it does not require liquids to attain their boiling points.
Factors affecting Evaporation
Evaporation can get affected by a number of factors as listed below –
Temperature: An increase in temperature leads to an increase in the rate of
evaporation.
Surface area: An increase in the surface area of the substance leads to an
increase in the rate of evaporation.
Humidity: The amount of water vapour present in the air is called humidity. As
humidity increases, the rate of evaporation decreases.
Wind speed: An increase in wind speed leads to an increase in the rate of
evaporation.
What is the difference between evaporation and vaporization?
Although these terms get used interchangeably quite often because of their
similarities, evaporation, and vaporization in fact differ largely on a molecular
level.
VAPORIZATION EVAPORATION
DEFINITION
It is defined as the transition phase of a compound
or element at boiling temperature.
It is the process that most often occurs at
temperatures below the boiling point.
TRANSITION OF
STATE
It changes the state of matter from solid or liquid to a
gaseous state.
It directly converts the liquid state of matter into
gas.
SPEED OF PROCESS This is usually much faster and requires less energy.
It is a very slow process that requires more
energy.
AFFECTED AREA
In the process of vaporization, the entire substance
turns to gas.
During the evaporation process, only the top-
level water becomes gaseous.

3. www.takshilalearning.com call 8800999284
MOVEMENT OF
MOLECULES
Molecules can form on the surface of the liquid.
Molecules only evaporate from the surface of
the liquid.
There is very little difference between vaporization and evaporation once liquids
or solids turn into a gaseous form as condensation of gas as gas from both,
evaporation and vaporization can turn into liquid as gas gets cooled.
However, a fun thing to notice is that the transition between the states of matter
from one to another occurs without any change in the chemical composition of
the substance. Therefore, these changes are only considered as physical
changes and not chemical changes. To get an understanding of physical and
chemical changes, check out our blog.
Related Grade 9 Science Notes
Magnetism and Electromagnetism Class 9 Science Worksheet
What is Matter? Class 9 Science
How do vaccines work in our body
Prepare CBSE Online Class 9 with our 9th Online Tuition Classes and
Interactive Live Online Classes