Grade Six Science
Hello Boys and Girls,
How are your studies coming along? Are you doing your homework and revising as much as you can? Have you been enjoying our work on matter? Below you will find a wordsearch for you to complete. Find the words: solution, solute, solvent, soluble, insoluble, water, mixture, mix, dissolve, matter, liquid, air, gas, solid. Have fun.
Last week we found out about solutes, solvents and solutions. I hope you had lots of fun with the exercises. This week we’ll find out about the composition of air.
Of what is air composed? Yes, air is really a mixture of invisible gases. Can you name one of these gases? Oxygen is one of the important gases in the air. It makes up 21 percent (21%) of the air. Oxygen is needed in respiration and for burning. Can you suggest other uses? Nitrogen is another gas that is found in the air. It takes up about 78 percent of the air. It is the most common gas in the air. It is important in the making of ammonia used in fertilizers.
Have you ever heard of the gases neon and argon? They are sometimes called rare gases because they are not found in large amounts in the air. They are used to fill electric light bulbs and advertising signs. I’m sure that you’ve heard of helium balloons. Helium is a very light gas that is often used to fill weather balloons which are sent up in the air to record weather changes.
Carbon dioxide is another gas found in the air. It forms only a very small part of the air around us. Carbon dioxide is forced into drinks to make then fizzy. Water vapour is also found in the air.
So we have learnt that oxygen makes up approximately 21% of the air, nitrogen 78%, and the other gases only 1%.
Answer the following
1. What is air?
2. Name four gases found in the air.
3. Which gas is most common?
4. The gases ________________ and _______________ are found in many
electric light bulbs.
Is air important for burning? Let us find out. You will need – Three candles of the same size
♦ A small jar
♦ A large jar
♦ Three dishes
♦ Matches
(NB. A grown-up should be with you at this time!)
The candle in the small jar goes out first. The candle in the larger jar burns for a longer time as there is more air in the larger jar. The uncovered candle keeps on burning. It is exposed to oxygen from lots of air around it and air is necessary for burning.
Let’s see how much you remember.
Light a candle and let a bit of the liquid wax fall into a tin lid. Blow out the candle and push the candle into the wax. Repeat this for the other two candles.
Next light the three candles and cover two of the candles at the same time with the jars – one with the small jar and the other with the large jar.
Now observe how the candles burn. Answer the following questions – i. Which candle goes out first? ii. Which candle goes out next? iii. Which candle burns for the
longest time? iv. Explain why the candle that went out before the second candle did so. v. Explain why the uncovered
candle continues to burn.
Put True or False for each statement that follows
1. Air is found only in some places around us . ................
2. Air can be found even in an empty glass . ................
3. We can know that air moves when we see the leaves of a tree moving.
............
4. We can see air. ................
5. Air occupies space . ...............
Call up a friend and compare your answers. Did you get F T T F T (#1 - 5)?
Now let us do a simple experiment to find out more about air.
Things you need –
√ A large bowl of water √ Two jam jars
i. Fill one of the jam jars (jar 1) with water and lower it onto its side into the
bowl so that at stays full of water. ii. Push the other empty jar (jar 2) upside down, straight down into the water
so that it stays full of air. iii. Now bring the necks of the two jars close to each other. See if you can pour
the air from jar 2 to jar 1.
Did you see the bubbles of air go into jar 1, and push the water out of the way? As the air leaves jar 2, there will be space for water to run into it.
Try it again.
Now see if you can end up with air in jar 1 and water in jar 2.
Does air have mass (‘weight’)? What do you think? Let’s find out. You will need –
i. Two balloons Two similar tins A pin Scissors
i. A long thin stick
i. A pencil i. String
Blow up the balloons so that they are the same size. ii. Tie the necks with pieces of string of the same length, and then tie the
strings to the ends of the stick. iii. Balance the stick and the balloons on the tins and pencil. Make sure that the
balloons are at the same level. iv. Now punch the pin into one of the balloons. What happens?
Did you hear a bang as the air rushed out? The burst balloon has lost most of its air. Did the stick tip over? The full balloon is heavier. The balloons themselves are the same, so it is the air inside the balloon that has mass. Air has mass!
This is all for now. I hope that you enjoyed the word search and the other exercises. Please remember to wear your masks if you must leave your home. Wash your hands often and keep at least six feet away from others.
Until next week, goodbye Boys and Girls!
Hello Boys and Girls! I hope that you are safe and you are diligently completing your work. This week we will look at Cuboids.
What is a Cuboid?
A cuboid is a three dimensional shape made from 6 rectangles, which are placed at right angles. A cuboid that uses square faces is a cube, if the faces are rectangles, other than cubes, it looks like a shoe box. A cuboid is a prism because it has the same cross-section along a length. It is a rectangular prism.
Properties of a Cuboid
● It has 12 edges
● It has 8 corners or vertices ● It has 6 faces
THE NET OF A CUBOID
Cuboid nets are the laid out 2-dimensional faces that can be folded to make the 3-dimensional shape of a cuboid. Cuboid nets are used in mathematics to aid in the teaching of 3-dimensional shapes. They enable us to see the shapes of the faces that make up the 3D shape.