Lesson 3

Change of appearance

What are physical changes of matter

A physical property of matter is any property that can be observed or measured without changing the chemical identity of a  substance.

A physical change is a change that affects one or more physical properties of a substance.The appearance, shape, or size of a substance may be altered during a physical change.

Changes of a state, and all physical changes, do not change the chemical make up of the substance, an example of a physical change happens when you feel an ice cube tray with water and place it inside a freezer.

What are chemical changes of matter?

A chemical change occurs when one or more substances chenge into an entirely new substance with different properties.

Chemical changes are not exactly the same as chemical properties. Burning is a chemical change, and flammability is a chemical property.

Indicators of chemical changes

Some indicators are:

• Production of an odor: 
• Production of gas
• Formation of a precipitate
• Change in energy
• Change in color 

Lesson 2

What are physical properties of matter?

They are used to describe a substance.

A characteristic of a substance that can be observed and measured without changing the identity of the substance is called a physical property. For example: color , shape, seize, and texture.

Common Physical Properties:

Density: is a measure of the amount of mass in a given amount of volume.

Electrical conductivity: is a measure of how well an electric current can move through a substance.

Solubility:  is the ability of substance to disolve in another substance.

Maleability : is the ability of a substance to be rolled or pounded into various shapes.

Melting Point: the melting point of a substance is the temperature at wich it changes from a solid to a liquid.

What are chemical properties of matter?

A Chemical property describes a substance's ability to change into a new substance with different properties. They describe how a substance changes and they can be observed only as the identity of a substance changes. For example: Ripening is a chemical property 

What's the difference between physical and chemical properties?

   A physical property can be observed without changing the identity of a substance, for example: determining the mass of the substance does not change its identity. And a chemical property can be observed only by changing the identity of a substance., for example :flammability and reactivity.

Lesson 1 : Matter !

Lesson 1

Do you know what matter is? 

Matter is anything that has mass and takes up space,however not everything is matter. 

For example: light and sound are not matter, but a pencil or a book are matter.

Mass is the amount of matter in an object.
Weight is a measure of the gravitational force.An object´s weight can change depending on the object´s location. For example: You would weigh less on the moon than you do on Earth because of the gravitational force.

 Volume: the amount of space that an object  takes up.
Density : the amount of mass in a given volume.

Formulas: 

To find an object´s density you have to divide its mass by its volume.

To find an object´s mass you have to multiply its density and its volume.

To find an object´s volume you have to multiply length, width and height

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