Toribio Minor National High School
Quarter 3
Poblacion, Margosatubig, Zamboanga del Sur
Science 8
S.Y. 2023-2024
Study Notes
Name: _________________________________________________________________
Date: February 15, 2024
MELCS:
Explain the properties of solids, liquids, and gases based on the particle nature of matter. (MELC Week 1-2 S8MT-IIIa-b-8)
Study Notes:
Lesson 1: Particle Nature of Matter
Matter has three states namely: solid, liquid and gas. Each state has different arrangement of particles.
Solid

It has definite shape and volume because its particles are closely packed together in a fixed position. These
particles vibrate and are held together by strong attractive forces. It is difficult to compress the particles.
Liquid

It has a definite volume and takes the shape of the container. Liquid flows easily because its particles have
enough space and have less attractive force. The spaces in the particles allows particles to be compressed a
little bit.
Gas

It takes the volume and shape of the container. Gas particles are far from each other that is why they have the
weak attractive force and can flow easily. They occupy the entire space available. The large spaces in between
particles allows particles to be compressed easily.
PROPERTIES OF SOLIDS
 DENSITY- is the measurement of how tightly a material is packed together. It is defined as the mass per unit
volume.
Density Symbol: D or ρ
Density Formula: ρ =m/V, where ρ is the density, m is the mass of the object and V is the volume
of the object.
 CRYSTALLINE SOLIDS- The individual pieces of crystalline solids are called crystals. Crystalline solid is a
solid whose atoms, ions, or molecules are arranged in an orderly, geometric, three dimensional structure.
 METALLIC SOLIDS- consist of positive metal ions surrounded by a sea of mobile electrons. Mobile electrons
make metals good conductor of heat and electricity.
 AMORPHOUS SOLIDS- is one in which particles are not arranged in a regular, repeating pattern. Amorphous
means “ without shape” in Greek.
PROPERTIES OF LIQUIDS
 FLUIDITY-is the ability to flow. Gases and liquids are classified as fluids because they can flow.
 VISCOSITY- is a measure of the resistance of a liquid to flow. The particles in the liquid are close enough for
attractive forces between them. It is the state of being thick, sticky, and semifluid in consistency, due to internal
friction
- Particle Arrangement: The viscosity of a liquid is influenced by the arrangement of particles. In
liquids, particles are in constant motion, and viscosity increases with the degree of intermolecular
attraction.
- Particle Behavior: Stronger intermolecular forces result in higher viscosity as particles resist
sliding past each other more.
***TEMPERATURE- is a measure of the average kinetic energy of the particles in an object.
 Boiling Point and Melting Point:
Particle Arrangement: The strength of intermolecular forces affects these points. In liquids,
particles have enough energy to move past each other, but strong intermolecular forces require
more energy for a phase transition.
Particle Behavior: The boiling point is reached when the vapor pressure equals atmospheric
pressure, allowing particles to break free and become a gas. The melting point is when particles
gain enough energy to transition from a fixed arrangement in a solid to a more mobile arrangement
in a liquid.
 SURFACE TENSION- is the energy required to increase the surface area of a liquid by a given amount.
Particle Arrangement: The surface tension of a liquid is related to the cohesive forces between
particles at the liquid's surface.
Particle Behavior: At the surface, particles experience a net inward force due to unbalanced
cohesive forces, leading to the formation of a "skin" or surface layer.
 CAPILLARY ACTION- is the ability of a liquid to flow in narrow spaces without the assistance of, or even in
opposition to, external forces like gravity.
 Density - Liquids vary in density. The density of a liquid with a constant volume varies according to the weight.
The greater the weight, the higher the density.
Particle Arrangement: In liquids, particles are closely packed but not in a fixed, orderly
arrangement like in solids. They have more freedom to move around.
Particle Behavior: The density of a liquid is determined by the mass of particles in a given volume.
The close packing of particles contributes to the relatively high density of liquids compared to gases.
 Solubility:
Particle Arrangement: Solubility depends on the interactions between solute and solvent particles.
Particle Behavior: If the intermolecular forces between solute and solvent particles are similar,
the substances are more likely to be soluble.
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Toribio Minor National High School
Quarter 3
Poblacion, Margosatubig, Zamboanga del Sur
Science 8
S.Y. 2023-2024
Study Notes
PROPERTIES OF GAS
VOLUME- Gases do not have definite volume. This means that a gas will fill whatever volume is available.
The volume of gas is measured using a calibrated tube called burette. The SI unit for volume is cubic
meter but often use liter (L) and milliliter (mL) or cubic centimeter.
Lesson 2: The Phase Change
1. Identify phase changes;
2. Describe how matter undergoes phase change; and
3. Explain physical changes in terms of the arrangement and motion of atoms and molecules. (MELC Week 3-4 S8MTIIIc-d-9)
Matter undergoes phase changes. The phase change is a change
from one state to another without changing the chemical composition of
a substance. There are six phase changes that matter can undergo.
Melting is the change of matter from solid state to a liquid state.
When liquid state changes back to a solid state, this phase change is called
freezing/solidification. Evaporation is changing matter from the liquid
state to gas state, while condensation is the change from the gaseous
state to liquid state. When solid state directly changes to gas without
passing the liquid state, it is called sublimation. In addition, deposition
is the change from a gaseous state directly to solid state.
Increasing the temperature will result in the increase of kinetic
energy (motion) of particles and this will affect the current arrangement
of the particles in solid, liquid and gas. As the temperature and the kinetic
energy are both increase, the tiny particles move, resulting to a farther
distance between the particles. Decreasing the temperature will result in
the decrease of kinetic energy (motion) of particles, leading to a closer distance between the particles. The lower the
temperature and the kinetic energy, the closer the particles are together.
Phase Changes on the Molecular Level:
1. Kinetic Molecular Theory:
Describes the behavior of matter at the
molecular level.
Molecules are in constant motion, and their
kinetic energy determines the state of matter.
2. Solid State:
Molecular Arrangement:
o Molecules are tightly packed in a regular,
ordered pattern.
o Vibrational motion around fixed positions.
Intermolecular Forces:
o Strong forces (van der Waals, hydrogen
bonding) hold molecules in fixed positions.
o Minimal kinetic energy limits movement.
3. Liquid State:
Molecular Arrangement:
o Molecules are close together but more
disordered compared to solids.
o Random
translational,
rotational,
and
vibrational motion.
Intermolecular Forces:
o Weaker forces compared to solids, allowing for
more movement.
o Molecules can slide past each other.
Transition to Liquid:
o Absorption of heat energy overcomes
intermolecular forces.
o Molecules gain kinetic energy and transition to
a more disordered state.
4. Gaseous State:
Molecular Arrangement:
o Molecules are widely spaced and move freely.
o High kinetic energy with constant motion in all
directions.
Intermolecular Forces:
o Negligible forces between molecules.
o Gas particles move independently.
Transition to Gas:
Absorption of heat energy allows molecules to
overcome intermolecular forces.
o Increased kinetic energy leads to a transition
to the gaseous state.
5. Phase Changes:
Melting:
o Heat energy disrupts the ordered arrangement
of molecules in a solid.
o Molecules gain enough energy to break fixed
positions and transition to a more disordered
state.
Vaporization (Boiling/Evaporation):
o Heat energy overcomes intermolecular forces
in a liquid.
o Molecules gain sufficient energy to escape the
liquid phase and enter the gaseous state.
Condensation:
o Heat energy is released as gas molecules lose
kinetic energy.
o Molecules
slow
down,
re-establish
intermolecular forces, and transition back to
the liquid state.
6. Temperature and Molecular Kinetics:
o Increasing temperature increases molecular
kinetic energy.
o At specific temperatures (melting point,
boiling point), molecules gain enough energy
to undergo phase transitions.
7. Sublimation and Deposition:
Sublimation:
o Solid molecules gain enough energy to
transition directly to the gaseous state.
Deposition:
o Gas molecules lose enough energy to transition
directly to the solid state.
8. Equilibrium:
At each phase change, there is an equilibrium
point where the rate of molecules transitioning from one
phase to another is equal in both directions.
o
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Toribio Minor National High School
Poblacion, Margosatubig, Zamboanga del Sur
S.Y. 2023-2024
Quarter 3
Science 8
Worksheets
Name: _________________________________________________________________
Date: February 15, 2024
Grade and Section : ______________________________________________________
Score: ___________________
Activity 1. What changes take place?
Objective: Identify the phase change in matter.
Directions: Answer the questions that follow. Write your answer on the space
provided.
Lighted candle
1. What is your observation about the candle before it is lighted?
________________________________________________
________________________________________________________
What is your observation when the candle was lit?
________________________________________________________
How about after putting out the flame of the candle?
________________________________________________________
2. What state of matter is the lighted candle when it melts?
________________________________________________________
3. What process takes place when solid state changes to a liquid
state?___________________________________________________________________________________
4. How about when a liquid state changes back to solid? What is the process called?
________________________________________________________________________________________
Letting wet clothes to dry
5. What is your observation on the wet clothes before exposure to the heat of the
sun? ___________________________________________________________
*How about during the time of sun exposure?
___________________________________________________________
*Finally, after it was exposed to the sun?
___________________________________________________________
6. What process takes place when a liquid state changes to a gas state?
___________________________________________________________
7. How about when the gas state changes back to a liquid? What is the process
called?
____________________________________________________________
Toilet deodorizer placed in the comfort room.
8. What is your observation about the size of the toilet deodorizer based from the
given conditions?
A. Packed toilet deodorizer. ________________________________________
B. Unpacked deodorizer after 5 days. ________________________________
C. Unpacked deodorizer after 15 days.________________________________
9. What causes the change in its size?__________________________________
_______________________________________________________________
10. What process takes place when solid state changes to gas state?
______________________________________________________________
Activity 2. Phase Changes Using the Particle Model of Matter
Objective: Explain phase changes using the particle model of matter.
Directions: Study the illustrations below. Then answer the questions that follow. Write your
answer on the space provided.
A.1 Refer to Figure 4.
1. What happens to the arrangement of
particles of matter in solid, liquid and
gas as the temperature increases?
________________________________________
________________________________________
________________________________________
________________________________________
2. What happens to the kinetic energy of
particles of matter in solid, liquid and
gas as temperature increases?
________________________________________
________________________________________
__________________________________________
__________________________________________
Strengthening
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Toribio Minor National High School
Poblacion, Margosatubig, Zamboanga del Sur
S.Y. 2023-2024
Quarter 3
Science 8
Worksheets
A.2 Refer to Figure 5.
3. What happens to the arrangement of
particles of matter in solid, liquid and
gas as the temperature decreases?
_________________________________________
_________________________________________
_________________________________________
4. What happens to the kinetic energy of the
particles of matter in solid, liquid,
and gas as temperature decreases?
_________________________________________
_________________________________________
_________________________________________
B. Describe the motion and arrangement of particles in each state as temperature changes. Fill in
the table with the correct answer. Write your answers on the space provided. Number 1 is done for
you as an example.
Phase Change
Temperature
(increasing or
decreasing)
Motion (Kinetic
Energy)
(fast or slow)
Arrangement of
particles
(very close, close or far)
increasing
fast
close
1. Melting
(Solid – Liquid)
2. Evaporation
(Liquid-Gas)
3. Sublimation
(Solid-Gas)
4. Deposition
(Gas-Solid)
5. Condensation
(Gas-Liquid)
6. Freezing
(Liquid-Solid)
Activity 3. Fill me in!
Directions: Identify the phase change involved by filling in the blanks. Write your answers on the
space provided for.
Figure 7. The Phase Changes
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Toribio Minor National High School
Poblacion, Margosatubig, Zamboanga del Sur
S.Y. 2023-2024
Quarter 3
Science 8
Worksheets
Activity 4. Phase changes in our environment!
Directions: Identify the phase changes shown in the picture. Make a presentation on how water
behaves in its states within the water cycle(You can make the presentation by drawing the particles
behavior in each phase change.).
Answer:
________________________________________________________________________________________________
________________________________________________________________________________________________
________________________________________________________________________________________________
________________________________________________________________________________________________
________________________________________________________________________________________________
Scoring Rubrics
3 – Discussions do not have misconceptions; with complete scientific evidence.
2 – Discussions do not completely show scientific evidence.
1 – Discussions do not show complete scientific evidence; with misconceptions.
0 – There is no discussion shown.
Activity 5. Fill in the blanks
Directions: Fill in the blanks with the correct answers. Write your answers on the space provided
for.
Phase change is the change of state of substance undergoing from one form to another. The
chemical composition of the substance is retained even when it undergoes phase change.
Matter undergoes phase change due to the change in temperature. The higher the
(1)___________ and the kinetic energy, the faster the tiny particles move resulting to the farther
distance of the particles from each other. The lower the temperature and the (2) ___________, the
particles move slowly leading to a closer distance of the particles.
As liquid water evaporates, its temperature (3) ___________and its kinetic energy increases. As
the water vapor in the form of clouds condenses, its (4) ___________ decreases and its kinetic energy
(5) ___________.
When ice melts, its temperature increases and its kinetic energy (6) ___________. As liquid water
solidifies, both its temperature and kinetic energy (7) ___________.
Source: CO_Q3_Science8_Module 2
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