Earth's rotations and revolutions
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
These two short online tutorials discuss how the earth rotates and then the earth's revolutions.
In the first URL, the YouTube video explains why earth has spring, summer, autumn and winter seasons. The second URL summarizes the key takeaway points.
The particle model of matter is one of the most useful scientific models because it describes matter in all three states. Understanding how the particles of matter behave is vital if we hope to understand science!
The model also helps us to understand what happens to the particles when matter changes from one state to another.
In this unit, you will explore the three phases of matter and then look at the properties and differences between them. You will explore their shape, volume, and kinetic energy.
In this unit you will learn about different materials by investigating and observing the behaviour of their properties. This will include learning about the differences between metals and non-metals; whether they are isolators or conductors of electricity and heat, whether they are magnetic, how dense they are and whether they are acidic or basic.
Electric charge comes in two varieties, which we call positive and negative. Like charges repel each other, and unlike charges attract each other. Thus, two positive charges repel each other, as do two negative charges. A positive charge and a negative charge attract each other.
How do we know there are two types of electric charge? When various materials are rubbed together in controlled ways, certain combinations of materials always result in a net charge of one type on one material and a net charge of the opposite type on the other material. By convention, we call one type of charge positive and the other type negative.
In this lesson you will learn that: