Notice that solids and liquids mostly have definite shapes, volumes and even densities.

Solid
particles are compact, which makes them exhibit stronger forces of attraction. The closely packed
structure and the strong forces of attraction among solid particles makes a solid material dense and
almost incompressible.
On the other hand, liquid particles are slightly close to one another with some spaces between
them. This molecular arrangement makes liquid particles slide over one another. This is the reason that
liquids take the shape of their containers and exhibit moderate forces of attraction.
SELF-LEARNING HOME TASK (SLHT) Gas molecules have almost negligible forces of attraction. This is due to the great distances
between gas molecules. The arrangement of gas particles makes them easy to compress.
Subject : SCIENCE Grade Level : 10
Quarter : 4th _
Week No. 1: April 4-8, 2022 Kinetic Molecular Theory of Gases
Kinetic Molecular Theory explains the behavior and properties of gases. The random
motion of gas molecules is one of the assumptions of the kinetic molecular theory (KMT) of
MELC: Investigate the relationship between: 1 volume and pressure at constant temperature of a gas 2
gases.
volume and temperature at a constant pressure of a gas 3 explains these relationships using the kinetic
molecular theory.
Assumption Concept
Postulate 1. Particle Volume A gas consists of a large collection of
Competency Code: S10MT – IIj-20
individual particles. The volume of an
individual particle is extremely small, as
Name: _Mary Juliasnne Cabiling_ Section: _10- COA_ Date: _4/12/22_ compared to the volume of its container.
Postulate 2. Particle Motion Gas particles are in constant, random,
Gases: The Moving Particles straight-line motion, except when they collide
with the walls of the container or with one
A. Readings/Discussions another.
Postulate 3. Particle Collisions Collisions of gas particles are elastic. The
Directions: Read the following information about gases: the moving particles for you to colliding gas particles or molecules exchange
be able to answer the exercises. energy, but they do not lose any energy
through friction. This means that the total
The air is composed of gases that are essential to life. Oxygen, a gas present in air, is kinetic energy is constant. Between collisions,
needed by human beings and other organisms. Carbon dioxide, another component of air, is the gas particles or molecules do not
needed by plants during photosynthesis. Other gases such as nitrogen and the noble gases are influence each other.
some of the components of the atmosphere that blankets Earth.
From this assumptions, we can now describe the physical quantities by which gas
Comparison of Solid, Liquid and Gas Molecules molecules are characterized.
Property Solid Liquid Gas  Volume. It is defined as the space occupied by a sample of matter. In this case,
Shape Has definite shape Takes the shape of its Takes the shape of its the gas molecules are the sample matter.
container container  Temperature. It is another physical quantity that affects the behavior of gas
Volume Has definite volume Has definite volume Takes the volume of particles or molecules. At a higher temperature, gas molecules move rapidly; at
its container a lower temperature, these molecules move slowly. Usually, it is measured in
Arrangement of Closely packed Close to one another, Very far apart from kelvin (K), Celsius (oC), or degree Fahrenheit (oF).
particles but with no regular one another  Amount of substance. This physical quantity is measured in moles (mol).
arrangement  Pressure. It is defined as the force exerted per unit area. Common units of
Compressibility Incompressible Compressible Very compressible pressure are atmosphere (atm), pascal (Pa), kilopascal (kPa), millimeters of
Density High Slightly dense Low mercury (mmHg), centimeters of mercury (cmHg), torr and sometimes, pounds
Movement of particles Slow Fast Very fast per square inch (psi).
Forces of attraction Strong Moderate
 1. A fixed amount of gas occupies a syringe with a volume of 6.0 L. The pressure
at 25 degrees Celsius is 1.00 atm. What will be the new pressure if the volume
Boyle’s Law (Pressure – Volume Relationship) becomes 3.0 L at the same temperature?
Given: P1 = 1.00 atm
V1 = 6.0 L
V2 = 3.0 L
P2 = ?
Formula: P2 = P1V1 / V2
Solution: P2 = (1.00 atm)(6.0 L) / 3.0 L
= 6.0 atm. L / 3.0 L
= 2.0 atm
Interpretation: Based on the given, it is expected that the pressure should
increase due to the decreasing amount of volume since pressure and volume are
inversely proportional to each other.
Let’s take a look first how a syringe works. Assuming that temperature is constant, the
pressure and the volume inside the barrel of the syringe change when you pull and push its plunger. 2. A certain amount of gas at 30 degrees Celsius occupies a container with an
When the plunger is pushed, greater pressure is applied and the amount of space the gas molecules adjustable volume. It currently has a volume of 11.0 L, with a pressure of 1.25
occupy inside the barrel of the syringe decreases; thus, the volume of the gas inside is decreasing. atm. What would its volume be if the pressure were adjusted to 1.50 atm?
However, when the plunger is pulled up, less pressure is exerted and the amount of space the gas Given: P1 = 1.25 atm
molecules can occupy increases; thus, the volume increases too. In other words, at constant P2 = 1.50 atm
temperature, when pressure increases, the volume of the gas molecules decreases; when pressure V1 = 11.0 L
decreases, the volume of gas molecules increases. This relationship between the pressure and the V2 = ?
volume of gases was investigated by an English scientist named Robert Boyle.
Formula: V2 = P1V1 / P2
Robert Boyle and Robert Hooke used a J-tube to measure the volume of a sample of gas at different Solution: V2 = (1.25 atm)(11.0 L) / 1.50 L
pressures. Using a J-shaped piece of glass tubing that was sealed on one end, he was able to establish = 13.75 atm. L / 1.50 L
the relationship between volume and pressure. Varying amounts of mercury were added to the J- = 9.17 L
shaped tube with gas system. He systematically varied the pressure and measured the volume of gas. Interpretation: Based on the given, it is expected that the volume should
These measurements were performed using a fixed amount of gas and a constant temperature. He decrease since the pressure increased from 1.25 atm to 1.50 atm. The volume
noticed that when the temperature is held constant, the volume (V) of a given amount of gas decreases decreased from 11.0 L to 9.17 L.
as the pressure (P) is increased. This experiment shows the relationship between pressure and volume
of gas at constant temperature. His experiment proved that pressure is inversely proportional to the 3. A cylinder of a scuba tank has a volume of 1500 mL at a pressure of 0.75 atm.
volume of gas at constant temperature; that is, the volume decreases with increasing pressure and vice What volume of air is needed to fill the cylinder to a pressure of 100 atm at
versa. constant temperature?
For a given sample of gas under two different sets of condition, at constant Given: P1 = 0.75 atm
temperature, V1 = 1500 mL
P1V1 = P2V2 (Boyle’s law) P2 = 100 atm
where: P1 – initial pressure; V2 = ?
P2 – final pressure;
V1 – initial volume; and Formula: V2 = P1V1 / P2
Solution: V2 = (0.75 atm)(1500 mL) / 100 atm
V2 – final volume
= 11.25 mL
The use of scuba tank in diving is a good application of the pressure-volume relationship of gas
Real Life Problems:
molecules. Seawater also contains dissolved gases such as carbon dioxide, nitrogen and oxygen. Scuba
divers going toward deep sea waters experience greater pressure. Thus, the volume of air that can enter
their lungs decreases, resulting in difficulty in breathing. This is why divers need special equipment.
However, ascending to the surface of the water will make the volume of the air inside the diver’s lungs 4. A gas, which is occupying a volume of 700 mL at a pressure of 0.85 atm, is allowed
expand. This is due to the change in pressure of the gas-from greater pressure at the lower part of the to expand (at constant temperature) until the pressure becomes 0.35 atm. What will
sea to lower pressure near the surface.
be the final volume of the gas?
Boyle’s law is significant in some technologies like in scuba, syringe, medical aspirator, balloon
pump and even in car engines.
B. Exercises
Directions: Determine the validity of the following statements that are related to the kinetic
molecular theory. Write “TRUE” if you agree with the statement and “FALSE” if you References:
disagree and write the correct answer on the space provided before each number.  Practical Science 10 pp. 304-316.
_______1. Gases consist of tiny particles.  World of Science for Critical Thinkers 10 pp. 263-279.
_______2. Gas particles do not attract each other.  www.genyo.com
_______3. The distance between gas particles are very small and can be  https://www.youtube.com/watch?v=YQmv272-4yU
assumed to be negligible.  https://www.youtube.com/watch?v=N5xft2fIqQU
_______4. The average kinetic energy of gas particles is inversely proportional  https://www.youtube.com/watch?v=v8r_AU_TlPg
to each other.
________5. The particles are in constant and random motion. However, there is no
collision between and among gas particles.

C. Assessment/Application/Outputs

Directions: You are a writer of stories for children. Your friend, who is an elementary
science teacher, needs your help and has asked you to write a story about the movement of
gas particles. Your friend will use this story as a learning tool for her students. Your story
must be interesting, creatively written and appropriate to the readers (grade four students).

Rubric:
Content and Organization – 20%
Insightfulness – 20%
Creativity – 10%

D. Suggested Enrichment/Reinforcement Activity

PROBLEM SOLVING
Directions: Solve the following problem using SPA (Systematic Problem Approach). 1 point for the
given, unknown and formula and 3 points for the solution.
1. What is the pressure required to compress 3500 L of hydrogen gas at 2.0 atm into a
50 L tank if the temperature is kept constant?
2. A 150 ml sample of gas has a pressure of 550 mmHg. What must be the pressure, at
constant temperature, if the volume is changed to 100 ml?
3. A gas occupies a volume of 250 ml at 300 mmHg of pressure. What will be its
volume if the pressure is doubled? Assume that the temperature is constant.
 As a result of his work with balloons, Charles noticed that the volume of gas is directly proportional to
its temperature which is now call as Charles’s law. His discovery on the relationship of temperature
and volume provides an explanation of how hot-air balloons work. Ever since, it has been known that
an object floats when it weighs less than that an object displaces. A larger volume is occupied by gas
when it is heated and less is occupied when it cooled. This is because hot air is less dense than cold air.
Once the air in balloon gets hot enough, the net weight of the balloon plus this hot air is less than the
weight of an equivalent volume of cold air outside, and the balloon starts to rise. When the gas in the
SELF-LEARNING HOME TASK (SLHT) balloon is allowed to cool, the balloon shrinks and returns to the ground.

Subject : SCIENCE Grade Level : 10 Charles’s law can be demonstrated with a simple experiment. Using a thermometer that is inserted
Quarter : 4th _
Week No. 2: April 11-13, 2022 through a rubber stopper into a flask and a 30 ml syringe that has been cooled to 0 0C in an ice bath.
The ice bath is then removed and the flask expands as it warms, slowly pushing the piston out of the
MELC: Investigate the relationship between: 1 volume and pressure at constant temperature of a gas 2 syringe. The total volume of the gas in the system is equal to the volume of the flask plus the volume
volume and temperature at a constant pressure of a gas 3 explains these relationships using the kinetic of the syringe.
molecular theory.
Jacques Charles came up with a mathematical equation of the dependence of volume to the
Competency Code: S10MT – IIj-20 temperature of gas at constant pressure. For a given sample of gas under two different sets of
conditions, then
Name: ___________________________________ Section: ______________ Date: _______
V1/T1 = V2/T2
Gases: The Moving Particles where: P1 – initial pressure;
P2 – final pressure;
A. Readings/Discussions T1 – initial temperature; and
T2 – final temperature
Directions: Read the following information about gases: the moving particles for you to
be able to answer the exercises. Sample Problems:
1. A balloon has a volume of 2500 ml on a day when the temperature is 303 K. If the
Charles’ Law (Volume – Temperature Relationship) temperature at night falls to 283 K, what will be the volume of the balloon if the pressure
remains constant?
Have you experienced riding a hot-air balloon? The clear skies in Subic, Zambales is the home of the Given: V1 = 2500 L
Hot-air Balloon Festival, wherein you can see colorful hot-air balloons in the sky. But have you ever T1 = 303 K
wondered how hot-air balloons lift off and fly in the sky? The answer lies in the relationship between T2 = 283 K
the volume and the temperature of gas molecules inside the balloon. V2 = ?

Boyle’s Law depends on two factors-pressure and volume at constant temperature. But, what if the Formula: V2 = V1T2 / T1
temperature changes? How will the pressure and volume be affected when the temperature change? Let Solution: V2 = (2.5 L)(283 K) / 303 K
us take a look at the effect temperature to the volume of the gas. = 707.5 L.K / 303 K
Hot air balloons stay up in the air by manipulating the temperature of air inside the balloon. As air = 2.33 L or 2330 mL
becomes hotter, the gas particles in it vibrate faster, increasing the distance between each particle, and Interpretation: According to Charles law, a decrease in temperature from 303
resulting in an increase in volume. As more heat is absorbed or stored by the balloon, its volume K to 283 K could cause the volume to decrease from 2500 mL to 2330 mL,
becomes greater. It begins to rise in the air when there is enough difference between the volume of air since they are directly proportional to each other.
outside the balloon and the volume of air inside the balloon to make the balloon more buoyant.
2. If 15.0 L of neon at 60 degrees Celsius is heated at constant pressure, what temperature
Jacques Alexandre Charles immediately tried to duplicate the experiment of Joseph Michel and will it have if it occupies a volume of 4.50 L?
Jacques Etiene Montgolfier that used fire to inflate a spherical balloon that traveled more than a mile. Given: V1 = 15 L
 T1 = 60 0C Interpretation: A final pressure of 1.50 atm from 0.75 atm was caused by an
V2 = 4.50 L increase in the temperature. Changes in the temperature casue the pressure to
T2 = ? change also.

Formula: T2 = V2T1 / V1 2. Determine the new pressure when a constant volume of gas at 1.00 atm is heated from 25
degrees Celsius to 35 degrees Celsius.
Solution:
A. Converting 60 0C to Kelvin scale. Given: P1 = 1.00 atm
= 60 0C + 273 K T1 = 25 0C or 298 K
= 333 K T2 = 35 0C or 308 K
P2 = ?
B. Finding for the final temperature, T2
T2 = (4.50 L)(333 K) / 15 L Formula: P2 = P1T2 / T1
= 1498.5 L.K / 15 L Solution: P2 = (1.00 atm)(308 K) / 298 K
= 99.9 K = 308 atm.K9 / 298 K
Interpretation: The temperature is expected to decrease from 333 K to 99.9 K = 1.03 atm
due to a decrease in the volume of the Neon gas from 15 L to 4.50 L as stated
any decrease in the temperature could cause a decrease in the volume.

Imagine you have a balloon inside a container that ensures it has a fixed volume. You heat the B. Exercises
balloon.
 What is happening to the temp of the gas inside the balloon? Directions: Select the single best answer.
 What will happen to the pressure the gas is exerting on the balloon? 1. Which of the following exhibits Charles’s Law?
a. Using a syringe
In Gay Lussac law, the pressure and absolute temperature (K) of a gas are directly proportional (as b. Using a pressure cooker
temperature rises, so does pressure) at constant mass & volume.
c. Rising of dough when baked
Gay-Lussac’s Law leads to the mathematical expression: d. Throwing an aerosol can to a flame
*Assuming volume remains constant 2. An unknown gas has a volume of 300 ml at 323 K. What will happen to its
P1/T1 = P2/T2 temperature if the volume increases to 600 ml?
a. It will increase.
Egg in a bottle to show Gay-Lussac's Law: b. It will decrease.
T & P relationship: c. It will remain the same.
d. There will be no change.
Sample Problems:
1. A fixed amount of gas has a pressure of 0.75 atm with a temperature of 30 degrees Celsius. 3. One hot day, a 50 ml corn chip bag at a temperature of 60oC was left inside the car.
At what temperature will the pressure be doubled if the volume is kept constant? What happens to the volume of the bag if the temperature decreases to 20 oC?
Given: P1 = 0.75 atm a. Increase in V, decrease in T
T1 = 60 0C or 303 K b. Increase in V, increase in T
P2 = 1.50 atm c. Decrease in V, decrease in T
T2 = ? d. No change in V, increase in T
4. Why does pressure build up in a tire on a hot day?
Formula: T2 = P2T1 / P1
a. As temperature increases, the gas pressure also increases.
Solution: P2 = (1.50 atm)(303 K) / 0.75 atm
= 454.5 atm.K / 0.75 atm b. As temperature increases, the kinetic energy of the molecules increases.
= 606 K c. As temperature increases, the kinetic energy of the molecules decreases.
 d. As temperature decreases, the kinetic energy of the molecules decreases.
5. An amount of hydrogen gas was placed inside a sealed vessel at 200C. The References:
temperature of the gas was raised to 600C. The pressure inside the vessel was  Practical Science 10 pp. 319-322.
observed to rise. What will explain this observation?  World of Science for Critical Thinkers 10 pp. 284-291.
 https://www.youtube.com/watch?v=uZ2d79NFx2w
a. The gas molecules expand as the temperature rises.
 https://www.youtube.com/watch?v=RszgzH_2A9k
b. The gas molecules are breaking down into separate atoms
 https://www.youtube.com/watch?v=oEZbkXB3y1Q
c. .
d. The gas molecules are being forced farther apart by the addition
e. The gas molecules are striking the walls of the vessels with increased
average speed.

C. Assessment/Application/Outputs

Directions: You are a writer of stories for children. Your friend, who is an elementary
science teacher, needs your help and has asked you to write a story about the movement of
gas particles. Your friend will use this story as a learning tool for her students. Your story
must be interesting, creatively written and appropriate to the readers (grade four students).

Rubric:
Content and Organization – 20%
Insightfulness – 20%
Creativity – 10%

D. Suggested Enrichment/Reinforcement Activity

I. PROBLEM SOLVING
Directions: Solve the following problem using SPA (Systematic Problem Approach). 1
point for the given, unknown and formula and 3 points for the solution.
1. Determine the pressure change when a constant volume of gas at 1.00 atm is
heated from 200C to 250C.
2. A 35 L volume of carbon dioxide gas is heated from 350C to 750C, at constant
pressure. What is the final volume of the gas?
3. Under constant pressure, a sample nitrogen gas, initially at 77 0C and 7.7 L, is
cooled until its final volume is 2.5 L. What is the final temperature of the gas?
II. ESSAY
Directions: Explain your answers briefly and concisely in no less than four (4)
sentences. Content – 3 and Grammar – 2.
Use the kinetic molecular theory of gases to explain briefly the following
observations:
a. An aerosol can explode when thrown in a fire.
b. LPG tanks should be placed in dry and cool places.