Differences Between Physical and Chemical Change are as follows Physical Change Chemical Change When a substance undergoes a physical change, its composition remains the same despite its molecules being rearranged. When a substance undergoes a chemical change, its molecular composition is changed entirely. Thus, chemical changes involve the formation of new substances. Physical change is a temporary change. A chemical change is a permanent change. A Physical change affects only physical properties i.e. shape, size, etc. Chemical change both physical and chemical properties of the substance including its composition A physical change involves very little to no absorption of energy. During a chemical reaction, absorption and evolution of energy take place. Some examples of physical change are freezing of water, melting of wax, boiling of water, etc. A few examples of chemical change are digestion of food, burning of coal, rusting, etc. Generally, physical changes do not involve the...

  Physical Changes In a physical change, a substance undergoes changes only in its physical properties such as shape, size, colour and state, and no new substance is formed. First, we shall perform some activities to show the physical changes that are taking place all around us are: Characteristics of Physical Changes The physical changes are temporary changes which can be easily reversed to form the original substance. In such a change, no new substance is formed. Thus, we noticed that the important characteristics of physical changes are as follows: No new substance is formed in this change. It is a temporary change and is generally reversible. A temporary change in colour may take place. Very little energy (heat, etc) is either absorbed or evolved. Everyday Examples of Physical Changes With Water The physical changes of water are easy to see at home, at work, or even in nature. An ice cube melting into water in your drink Freezing water to make ice cubes Boiling water evaporatin...

  Observations that indicate a chemical change Heat or light is absorbed or given out during a chemical reaction. Production of sound Production of gases or precipitates Production of smell A colour change may occur Rusting When substances made of Iron are exposed to oxygen and moisture in the atmosphere, it forms a red layer, which is called  rust . The formation of rust can be represented by the following reaction: 4Fe + 3O 2  → 2Fe 2 O 3 .  The chemical formula for rust is Fe 2 O 3 .nH 2 O. More the moisture in the air, quicker the formation of rust Galvanization – The process of depositing zinc on the surface of Iron to prevent rusting is called as  galvanisation . – Example: Iron water pipes are galvanised. Ships are made out of iron which is galvanised. Due to the presence of salts in seawater, the process of rusting is hastened. Hence ships need to replace their iron body every year. Crystallisation – The process of separation of salts from their sol...

  As we have discovered in the previous post Chemical changes are those which  change in which one or m ore new substances are formed. Below are various examples of Chemical change:   Metallic Oxides Formation of metal oxides are examples of chemical changes. They are formed by the reaction of oxygen in air. – Burning of Magnesium ribbon: – 2Mg + O 2  → 2MgO –  The product formed is the oxide of magnesium, which is in the form of ash. It does not look anything like the magnesium ribbon used for burning. Reaction of metallic oxides with water Reaction of metal oxides with water form metal hydroxides. Example dissolving Magnesium oxide in water, by stirring the ash very well with water. MgO + H 2 O → Mg(OH) 2 The product formed is basic in nature and turns red litmus paper → blue Reaction between baking soda and vinegar When a pinch of baking soda is added to vinegar we hear a hissing sound and observe the formation of bubbles. – Vinegar (Acetic Acid) + Baking Sod...

There are several changes we come across daily e.g. dissolving sugar in water, or flattening a metal rod by beating it. These involve changes in the form of the substance. Changes can be classified as: (i) Physical (ii) Chemical Physical properties Physical properties include size, shape, color and state (solid/liquid/gas) of a substance. Physical change Any change to the physical properties of a substance is called a physical change. Physical changes are usually  reversible  as no new substance is formed. It is the same substance but with changed physical properties. Chemical change A change in which one or more new substances are formed is called as a chemical change. Usually a chemical change involves a chemical reaction, which forms new products. Example : Rusting of Iron, or burning wood. Kindly refer to the following video for better understanding by Najam academy You can check what you learned on the following link https://forms.gle/5BjvjqWB4daHozjW8 Referenc...