Ecosystems
Chemistry
Astronomy
Electricity
100
In the monthly community newsletter, the group studying have tested out a local river for its PH level. When tested for its PH level. It is found to have a PH level of 4. However, in the newsletter, they mention that it is at a perfectly healthy PH level. Is this claim true or false? Justify your answer. (K)
This claim is false since the lake tested has resulted in a PH level of 4. If the PH level is at a healthy level it would need to be between PH 7-14. However, this is not the case. Hence, it is acidic, and does not obtain a healthy state.
100
When trying to see the reactivity of substances with other substances, they have brought an air tight container with substances in it. When they brought one out, it disappeared right away. a. What property has taken place, and why hasn't is happened before they took it out? b. Is it a chemical property or a physical property? (K)
a. What took place was the reaction of combustibility. This is when the substance has a direct reaction with the air. It did not occur prior to it being taken out since it was in an air tight container with no exposure to the air.
b. it is a chemical property.
100
The distance between earth and a star is 2 light years. How many km is this, and how far is 1 light year? (K)
1 Light year= 9.5 x 10^12
2 light years= 18922000000000 km
Therefore, the star is 18922000000000 km away from us.
100
Define the term 'Charge by friction' (K)
Charging by friction is a process in which objects made from different materials rub against each other, producing a net static charge on each.
200
Why is restoration ecology being done in society? (C)
It is done to restore what humans have destroyed through activities, and to ensure that the environment is clean, reserves, and protected post destruction.
200
Why do you think reactivity has something to do with a full valence electron shell? (I/T)
Answers may vary; Ex. I think it has something to do with the reactivity since if it does not have full valence shell, it can receive electrons from other atoms, and hence, react. However, when it has a full shell, it cannot gain electrons from other atoms, and will not react since it will not come in contact.
200
Why do you think another source should be used in spaceships as fuel along with solar energy? (I/T)
Answers may vary; Ex. In my opinion, i think another fuel source should be used since if the spaceship were to travel a distance very far from the sun, or are on a place where the sun is blocked from exposure, they still have a source of fuel and can manage.
200
Give 4 examples of renewable energy sources: (I/T)
4 examples can be waves, tides, biomass and geothermal
300
Why do you think the Kyoto protocol was put in place? (C)
Answers may vary: Ex. In my opinion, I think the Kyoto protocol was put in place to preserve the environment in the longer run. Since tree's will take long to grow, by the time they will be fully grown and be able to give out a good amount of oxygen, it would have passed many generations, and the area that was once depleted would now be sustainable.
300
Describe what Thomson Rutherford did in his experiment: (C)
What he did was that he radiated a sheet of gold on an alpha block. What occurred was that some of the alpha particles bounced of the alpha block, while some were absorbed. This is how he realized their was a nucleus, electrons, neutrons and protons.
300
When the scientists were studying the universe, they realized that the mass of the Milky Way is 90% more than its visible matter. However, they cannot think of what this is. a. What is this matter? b. Can we see it? (C)
a. This is called matter. It is the msot abundant form of matter in the universe, and takes up 90% of the mass.
b. No, we cannot see it, nor detect it. We can only prove its existence using the mass.
300
Draw a diagram of an electroscope an label all main points correctly: (C)
400
What is steward ship, and list one way we can contribute? (A)
Steward is the active understanding that it is our responsibility to take care of the environment. One way we can contribute to it is by planting tree's an not polluting the environment.
400
Draw a Bohr-Rutherford diagram of Titanium (A)
400
Can other planets have seasons? (A)
Yes, they can also have seasons since they also rotate while in revolution around the sun. However, it is not like the ones we would see on earth since they have a closer/ further distance from the sun.
400
After receiving community feedback, the scientists decided to take their last chance by exploring electricity, or else, they may be removed from the newsletter if not sucessful. They have come up with the following statement:"The electrical energy used by an appliance is calculated by multiplying the power rating (in kW) by the amount of time it is used (in hrs)" Is this true? (A)
Yes, this is true, as it will result in the unit for Killowatts/hour. Therefore, electricity is the best topic to explore for them.