Results

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.

This YouTube video investigates the structure and composition of the sun.

In this lesson you will learn about:

• The structure of matter
• Kinetic theory
• The three states of matter

Video 1: Strategies for subtracting decimals
Online activity 1: Subtracting decimals (tenths)
Video 2: Subtracting decimals (hundredths)
Video 3: More advanced subtraction strategies with hundredths
Online activity 2: Subtracting decimals (hundredths)

Part 1: Subtracting integers
Part 2: Examples of subtracting integers
Part 3: Common mistakes made when subtracting integers

Use two methods to find the sum of mixed numbers: improper fractions and mixed numbers

These four short online lessons cover the following:

• What is the sun?
• Interior of the sun
• Outer layers of the sun
• Surface features of the sun

This online resource investigates the internal structure, outer layers and surface features of the sun.

The phases of Meiosis.