States of Matter

1. Properties of matter in bulk are macroscopic properties. Examples are density, volume, viscosity of a liquid, surface tension of a liquid, resistance of a conductor and many more properties like these
   Microscopic properties are properties of constituents of the bulk matter, i.e. properties of atoms and molecules constituting the bulk matter.

2. Macroscopic vs Microscopic, we will look at the relationship between macroscopic and microscopic properties of matter Macroscopic properties can be observed in real life, and macroscopic quantities can be measured using laboratory appartus.

3. Microscopic properties are properties on the molecular level. They cannot be observed by any laboratory apparatus, and are only conceived in theoretical models.Examples include: pressure, volume, mass.

4. A physical change alters the form of matter, but not its chemical composition. In other words, physical changes affect physical properties of a substance, but not its chemical properties. The color, size, and shape of a substance may change, but no chemical reaction occurs and no new products form. Here are physical change examples, along with a look at how to tell a physical change from a chemical change.
   How to Identify a Physical Change
   Physical changes involve changes in physical properties. Certain processes result in physical changes:

   • Phase transitions: Melting, freezing, evaporation, and sublimation are all physical changes.

   • Heating and cooling: Temperature changes can result in phase transitions. Be careful, though, because sometimes adding heat supplies energy for a chemical reaction to occur.

   • Mixtures: In chemistry, components of a mixture retain their chemical identity. Use caution, because the general usage of the word mixture includes some chemical reactions! For example, you bake a cake by “mixing” ingredients, but this results in a chemical reaction.

   • Crystallization: Crystallization orders the arrangement of atoms and molecules, but does not change their identity.

   • Allotrope changes: Again, the arrangement of molecules changes, but not the chemical identity. For example, graphite and diamond are both allotropes of elemental carbon.

   • Magnetization: Magnetizing and de-magnetizing iron or another substance is a physical change.

   • Tempering: Tempering steel involves heating and hammering steel. While its hardness and flexibility change, its chemical composition does not.

5. Some physical changes are reversible, but others are not. However, reversibility usually indicates a physical change.
   Physical Change Examples
   Remember, in a physical change the appearance of matter changes, but its chemical composition remains the same. The size, shape, state, or color of matter may change. Here are several examples of physical changes:

   • Melting an ice cube

   • Crushing a can

   • Shredding paper

   • Boiling water

   • Mixing sand and water

   • Mixing sand and salt

   • Mixing oil and water

   • Breaking glass

   • Cracking an egg

   • Freezing water to make ice

   • Dissolving sugar in water

   • Melting sulfur (This causes a color change, even though the element remains the same. Many elements change color when they change phase.)

   • Filling a bowl with different colored candies

   • Sublimation of dry ice into carbon dioxide gas

   • Mixing flour, salt, and sugar

   • Chopping an apple

   • Breaking a rock

   • Evaporating liquid nitrogen

   • Mixing blue and yellow marbles

   • Mixing paint colors

   • Crumpling a paper bag

   • Melting wax

   • Origami (folding paper)

   • Making shapes from clay

   • Popping a balloon

   • Slicing bread

   • Tempering steel

   • Melting a crayon

   • Cutting your hair

6. Note that some changes are not reversible, such as cracking an egg, slicing bread, shredding paper, or breaking a rock.

7. Chemical Change When one chemical substance is changed into another substance, like when iron becomes rust, then this process is known as chemical change. Chemical changes are not simple to reverse or irreversible; therefore, it is said as a permanent change. Such changes lead to changes in physical and chemical properties, such as temperature, color, shape, taste, melting point, boiling point etc.

Difference Between Physical Change and Chemical Change

What is Physical Change?

Physical changes are the changes that affect the form of a chemical substance but not its chemical composition. The use of physical change is to disperse the mixture into their component compounds, but they cannot normally be used for the parting of compounds into simpler compounds or chemical elements.

In simple words, the kind of change where matter changes into other form without changing its chemical properties is known as physical change.

The properties like shape, size, state, density, solubility, luster, mass, volume and color of a substance are called its physical properties. The change in which a substance modifies its physical properties called physical change- For example; Crystallization.

Whenever substances or objects undergoes a chemical change, which does not alter their chemical composition, a physical change occurs.

The physical change only changes the substance's appearance, not it's chemical composition. A physical change means variations in physical properties. Physical change example, change of strength, color, melting, change of durability, volume, density, transaction to a gas, shape, size, textural change, change to crystal form.

What is Chemical Change?

When one chemical substance is changed into another substance, like when iron becomes rust, then this process is known as chemical change. Chemical changes are not simple to reverse or irreversible; therefore, it is said as a permanent change. Such changes lead to changes in physical and chemical properties, such as temperature, color, shape, taste, melting point, boiling point etc.

Through the process of chemical reactions, chemical changes occur. As a result, the substance has distinct properties because its atoms and molecules are differently arranged.

Example of Chemical Change

• Baking a cake

• Burning a candle

• Sourcing milk

• Rusting iron

• Mixing acid with base

Difference Between Physical Change and Chemical Change

1. What is the Law of Conservation of Energy?
   The law of conservation of energy states that energy can neither be created nor be destroyed. Although, it may be transformed from one form to another.the total energy of an isolated system always remains constant. All the forms of energy follow the law of conservation of energy. In brief, the law of conservation of energy states that
   
   In a closed system, i.e., a system that is isolated from its surroundings, the total energy of the system is conserved.

2. CLASSIFICATION OF MATTER: