Category: Grade Four Science

4th Grade LESSONS and EXERCISES

¬†Categories / Description MATH LESSONS: 4th Grade Didn’t understand something in school, check out these video explanations. MATH EXERCISES: 4th Grade Put the lessons you learn into practice. Try these animated exercises. LANGUAGE ARTS LESSONS: 4th Grade Need more tutorial in English? Check out these lessons. LANGUAGE ARTS EXERCISES: 4th Grade Put the lessons you…...

Experiment to Show Air Pollution

Air pollution is all around us. Air pollution began to attract people’s attention in the 1950’s, when people got sick and died as a result. The minute particles in the air that are not harmful unless inhaled in over long periods of time, are the substances causing the health issues. You can identify air pollution…

Sources of Air Pollution and Reduction of Harmful Effects

Air pollution consists of chemicals or particles in the air that can harm the health of humans, animals and plants. It can also damage buildings. Air pollutants can take different forms: gases, solid particles or liquid droplets. There are two main sources of air pollution: Natural or Man Made. Natural Sources Dust Storms: storms are…

Components of Air and How They are Used.

The air contains a number of gases. The more well known gases are: Nitrogen, Carbon Dioxide and last but not least Oxygen which is essential for human survival because we need it to breathe!! Other gases which are not as well known as the three mentioned above are listed below: Neon Methane Helium Krypton Hydrogen…

Properties of Air

Air takes up space, has matter, exerts pressure, is colourless and is all around us. It may be hard to imagine air as matter as a liquid or a solid because it seems to not have the properties mentioned above. For many years people didn’t think that air existed; but it does! Read these points…

Common Waterborne Diseases: Prevention and Treatment

The most commonly talked about water borne diseases are listed and briefly described below: Cholera This disease is caused by a bacteria in contaminated drinking water, rivers and coastal waters. Symptoms are watery diarrhoea, vomiting and leg cramps and can appear as soon as two hours after exposure to bacteria to as late as 5…...

Methods of Water Purification

There are many different methods of water purification. The ones important for your stage are listed and discussed here below. Boiling Water This is probably the simplest method of water purification. It is necessary to bring the water to a full or rolling boil for at least three to five minutes or longer, NOT WHEN…...

Water Pollution: Their Sources and Minimising their Effects

What is water pollution? This phenomenon occurs when toxic substances enter water bodies (eg. river), dissolve in them or lay suspended in the water. This degrades the quality of the water. This is a problem because the aquatic habitats can be destroyed, the pollutants can sleep through the ground water and end up in our…...

Other Simple Machines

Wheel and Axel This machine involves a circular rotating part (wheel) that turns around a shaft (axel). When one part turns, so does the other. Examples include a door knob and car wheels. Gears Wheels with teeth that fit into one another are called gears. As one gear turns so does the other. Gears can…...

Simple Machines: Levers

A machine is a tool designed to make work easier. Scientists define work as a force acting on an object to move it across a distance. Simple machines can magnify a force, change a force’s direction or increase the speed with which a force is applied. This changes the rate at which work can be…...

Complex Machines

Simple Machines are combined to form complex machines. A minimum of two simple machines together can be considered a complex machine. Complex machines are also referred to as compound machines. The size varies with each complex machine. It can be as small as a mechanical watch or as large as a car. Other examples of…...

Chemical Properties of Water

Be sure to check out all the posts on the Physical Properties of water!! Recall that the properties of water can be divided into two categories: chemical and physical. This post focuses on the chemical properties of water. Conductivity Regular water and electricity NEVER go together. I am sure that you have always been told…...

Physical Properties of Water: Part 3

This post is a continuation from “Physical Properties of Water: Part 2” Temperature:¬†Temperature exerts a major influence on biological activity and growth. Temperature governs the kinds of organisms that can live in rivers and lakes because aquatic species all have a preferred temperature range. As temperatures get too far above or below this preferred range,…...

Physical Properties of Water: Part 2

This post is a continuation from “Physical Properties of Water: Part 1” Water Density: Density can be described as how close together the molecules of a substance are or how much mass the same substance has in a given space. Take for example a cup of jelly beans and a cup of marshmallows. The cup…...

Physical Properties of Water: Part 1

Water has many different properties and can be divided into two broad categories: physical and chemical properties. Physical Properties Adhesion and Cohesion: In the simplest of terms, water adhesion refers to the attraction of water molecules to other substances and cohesion refers to the attraction of water molecules to themselves. You can think of it…...

Rocks and Minerals Worksheet–December 9, 2013

Complete the questions below. 1. What are the three major types of rocks? a. solid,liquid, gas b. igneous, sedimentary, limestone c. sedimentary, igneous, metamorphic d. lava, magma, mantle   2. Liquid rock above ground is called? a. mercury b. magma c. granite d. lava   3. Which of the following are layers of soil? a.…...