Unit 1: Sustainable Ecosystems
What is a sustainable ecosystem? (K)
A sustainable ecosystem is an ecosystem that is capable of withstanding pressure and giving support to a variety of organisms.
Why is a melting point considered a physical property? (K)
it is considered a physical property as it can be measured without changing the identity of the substance.
If a star's surface temperature is about 7200°, what colour will it be?(K)
It will be yellow-white.
You charge a balloon by rubbing it against your clothing. Then you stick it against the wall. Is it charged by contact or induction?(A)
It is charged by contact as it comes into contact with the wall.
Suggest a way that eutrophication due to human activities can be avoided. (C)
Answers may vary. For example, using pesticides far from a water source or planting trees beside a water source to avoid a run-off.
Which is more reactive: magnesium or calcium? (T/I)
Calcium is more reactive because the radius increases as elements get more reactive, and calcium has a bigger radius than magnesium.
Why is it safe to watch the eclipse of the Moon but not the eclipse of the Sun?(A)
It is safe to watch the eclipse of the Moon but not of the sun as it is safe to look directly at the Moon but not at the Sun as it can cause blindness.
Why does a D cell last longer than the A cell?(K)
The D cell contains the most electrolyte solution.
What are some possible reasons why scientists may not have an accurate count on the number of species on Earth?(T/I)
Answers may vary. For example, some species may live in deep parts of the ocean where scientists are not able to get to.
A new scam on the internet involves people selling samples of potassium that they collected from a secret pond in a cave. Explain why this is a scam. (C)
It is a scam as potassium is very reactive, and it is supposed to be left from water. If it comes into contact with water, it disappears.
Suggest a reason why scientists did not detect dark matter until the late 1990s.(T/I)
Answers may vary. For example, it is invisible and scientists can not detect it.
Why is it not safe to plug a three-prong plug into a two-slot socket? (T/I)
Answers may vary. For example,the electrons could emit smoke, causing a fire.
Why is the ecological footprint of a person in Canada higher than the global footprint?(A)
Answers may vary. For example, Canada has many resources and low-density population, so people may not use the resources sustainably and accordingly.
Which area do you think has more problems with rust: a town along the Atlantic ocean or a town in a remote area? Explain.(A)
The town along the Atlantic Ocean will deal with more rust as salt water reacts with rust faster than it would react with another substance.
Write a statement to prove that shooting stars are not really stars. (C)
Answers may vary. For example, Shooting stars are meteors, which means that they are rocks.
Explain why the user of an electric lawn mower must not connect several extension cords together when using a lawn mower. (C)
If several cords are put together, there is more resistance.