viernes, 12 de abril de 2013

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 





viernes, 15 de marzo de 2013

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.

viernes, 8 de marzo de 2013

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

viernes, 1 de marzo de 2013

Many people think that science is boring and useless, but we will try to make these blog different from all those other science blogs, we will post information that really matters, sometimes its interesting and will be usefull in our lifes.
Our blog is about scientific topics , we will be posting and uploading information, images and videos about interesting issues.We hope you enjoy reading it and also learn about our new info. Also you'll find important facts, key concepts and vocabulary about our science book.