Class 5 Exam  >  Class 5 Notes  >  Science Class 5  >  Detailed Notes: Solids, Liquids & Gases

Solids, Liquids and Gases Class 5 Notes Science

You will learn about

Molecules and atoms 

Element and compounds 

Arrangement of molecules in matter

Solutions and solubility

Change of state

Expansion and Contraction

Physical and chemical changes


Molecules and Atoms

Anything that occupies space and has mass is called matter. Matter exists in three states i.e. solids, liquids and gases. Matter is made up of tiny particles called molecules. We can define molecule as the tiny unit of a substance that has all the properties of that substance. A molecule cannot be seen with naked eyes. Molecules in different substances are arranged differently. Molecules can further be broken into atoms. They are called the building blocks of matter. Atoms are the smallest unit of a matter and cannot be divided further. 


Elements and Compounds

  • Atoms of the same kind combine to form elements.
  • Atoms of different kinds combine to form compounds.
  • Water is a common example of a compound which is made of two kinds of elements i.e. hydrogen and oxygen.

Arrangement of Molecules in Matter  

There are three states of matter solid, liquid and gas. Molecules in matters are always moving. They constantly attract each other and keep moving towards each other. All the three states have different arrangement of molecules. 

Table

  • Solids: In solids, the molecules are tightly packed. They attract each other with a strong force of attraction. There is no intermolecular space between the molecules so they cannot move. That is why solids have definite shape and volume. 
  • Liquids: In liquids, the molecules are not as closely packed as in solids. The force of attraction between the molecules is less as compared to that of solids. There is intermolecular space between the particles so that they can move freely. That is why liquids can flow. Liquids have definite volume but no definite shape. 
  • Gases: In gases, the molecules are far apart with large intermolecular spaces between them. They can move freely in all directions. So, gases can flow easily and take up all the available space. Gases do not have definite shape and volume. 

Solutions and Solubility

A solution is the mixture formed when a solute dissolves in a solvent. Solvent + Solute = Solution 

  • Some solids dissolve in water. We call them soluble substances.
    For example, sugar, salt, juices. 
  • Some solids do not dissolve in water. We call them insoluble substances.
    For example, sand, chalk, tea leaves, oil.

 Factors affecting Solubility

  • Stirring a Solution: Some substances dissolve quickly on stirring.
  • Temperature: More sugar can dissolve in hot water than in cold water.

How does a Solution Form?

 1. Solubility of Solids 

  • Solid solutes like salt, sugar, etc. dissolve in water to form solution. 
  • Molecules of the solute that are added to the solvent, occupy the space between the molecules of the solvent to form a new liquid, which is called a solution.

2. Solubility of Gases 

  • Just like solids, gases also dissolve in water and occupy the gaps in it.
  • Fizzy drinks are a solution of the gas carbon dioxide in water. The bubbles that you see in a fizzy drink are of carbon dioxide.
  • Water in lakes, ponds, seas, etc., has gases dissolved in them. Fish breathe the oxygen dissolved in water.

3. Solubility of Liquids

  • When two liquids can be mixed to form a solution they are called miscible.
    Example: Water and rose syrup are miscible.
  • When two liquids cannot be mixed to form a solution they are called immiscible.
    Example: Oil and water are immiscible.

 Water is called a universal solvent because it dissolves more substances than any other liquid.
This property is very important for life because it means that wherever water goes, either through the air, through the ground, or through our bodies, it takes along valuable chemicals, minerals, and nutrients dissolved in it.

Change of State 

Matter can change from one state to another on heating or cooling.

  • Melting: When ice is kept out of a refrigerator, it melts into water. The process of changing a solid into a liquid on heating is called melting.
  • Evaporation: When water is heated, it changes into water vapour. The process of changing of a liquid into a gas on heating is called evaporation.
  • Condensation: When the steam touches a cold surface, it changes into water. The process of changing a gas into a liquid on cooling is called condensation.
  • Freezing: When water is kept in a freezer, it changes into ice. The process of changing a liquid into a solid on cooling is called freezing.

Expansion and Contraction


  • When we heat a substance, the molecules start vibrating rapidly. Due to this intermolecular space between the molecules increases and the substance expands. Thus, expansion is the increase in size of matter on heating.
    Example: Electric wires between electric poles hang loose in summer season. 
  • On the other hand when we cool a substance, the movement of molecules slows down. Due to this intermolecular space between the molecules decreases and the substance contracts. Thus, contraction is the decrease in size of matter on cooling.
    Example: Electric wires do not hang loose between electric poles in winter season.  

Physical and Chemical Changes

  • Physical Change: A physical change is a temporary change that can be reversed. Original material remains same. In physical changes no new substance is formed
    Examples: boiling, melting, freezing, and shredding 
  •  Chemical Change: A chemical change is a permanent change that cannot be reversed. We cannot get original things back when a chemical change occurs in them. Inchemical changes new substances are formed.
    Examples: burning, cooking, rusting, and rotting 
The document Solids, Liquids and Gases Class 5 Notes Science is a part of the Class 5 Course Science Class 5.
All you need of Class 5 at this link: Class 5
44 videos|204 docs|45 tests

Up next

FAQs on Solids, Liquids and Gases Class 5 Notes Science

1. What is the difference between a molecule and an atom?
Ans. An atom is the smallest unit of a chemical element that retains its chemical properties, while a molecule is a combination of two or more atoms held together by chemical bonds.
2. What are elements and compounds?
Ans. Elements are substances that cannot be broken down into simpler substances by chemical means, and compounds are substances composed of two or more different elements chemically combined in a fixed ratio.
3. How are molecules arranged in matter?
Ans. Molecules in matter can be arranged in different ways, such as closely packed in a regular pattern in solids, more loosely packed in liquids, and far apart in gases.
4. How does a solution form?
Ans. A solution forms when a solute (substance being dissolved) is evenly distributed and mixed with a solvent (substance doing the dissolving) at the molecular level.
5. What is the difference between a physical and a chemical change?
Ans. A physical change is a change in the physical properties of a substance, such as a change in shape or state, without altering its chemical composition. On the other hand, a chemical change involves a rearrangement of atoms and results in the formation of new substances with different properties.
44 videos|204 docs|45 tests
Download as PDF

Up next

Explore Courses for Class 5 exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Related Searches

Solids

,

pdf

,

Liquids and Gases Class 5 Notes Science

,

Objective type Questions

,

Solids

,

Liquids and Gases Class 5 Notes Science

,

Exam

,

Viva Questions

,

Summary

,

Extra Questions

,

ppt

,

MCQs

,

past year papers

,

Previous Year Questions with Solutions

,

Free

,

practice quizzes

,

Semester Notes

,

Sample Paper

,

study material

,

Important questions

,

shortcuts and tricks

,

Liquids and Gases Class 5 Notes Science

,

mock tests for examination

,

video lectures

,

Solids

;