3. When chalk powder or sand is added to water it settles down. What do you conclude from this activity?
4. Gold and silver are used used to make jwellery. Give reason.
5. How will you show that water is a transparent material?
Answers
Answer:
Question 1:
When chalk is powder or sand is added to water it settles down. Conclusion from this activity are as follows:
a) The chalk powder and the sand are both solids that do not dissolve in water. This means that these solid compounds are insoluble in water.
b) The chalk powder and sand particles are more dense than the water molecules and this is why they settle at the bottom of the container.
Question 2
Why is gold and silver used to make jewellery?
There are simple reasons why these metals are used to make jewellery:
a) Their shiny attractive lustre/ nature makes them ideal for using them as jewellery.
b) These metals are both ductile and malleable - meaning they can be easily moulded into various shapes.
c) These metals are quite rare as well, making them valuable.
d) These metals, gold and silver, are almost unreactive in normal atmospheric conditions.
Question 3
How will you show that water is a transparent material?
Being transparent, simply means that you can see through water.
Here is an easy activity to show that water is transparent:
- Place water into an open container.
- Put a dense object into the water in the same container eg. a metallic coin.
- Look into the water to see if you can see the object at the bottom of the container through the water.
⇒You will be able to see the coin in the container through the water because water is transparent.
Answer:
shshsjeueu3ydbjdjdufudduudd