Unit 1
(K) Explain the meaning of the word "Ecosystem".
An ecosystem is a biological community of interacting organisms and their resources.
(T) Which of the following are not pure substances?
a) Element
b) Soil
c) white gold
d) Dimond
e) Compound
White gold and Soil
(K, T) Why does the moon have phases?
The moon has phases because, it orbits earth. This causes the position we see to illuminated to change.
(T, K) Explain why two electric charges might interact, even thought there is no contact between them?
They might interact because of the electric field. An electric field is the space between two objects.
(T) Explain three resources needed by polar bears besides, oxygen.
1. Nutrients
2. Cool temperature
3. Meat
(K) What is the use of a Bohr Rutherford diagram?
Bohr Rutherford diagrams are used to make an atomic model and show the number of electrons in each shell of an atom.
(T, I) What evidence is there that the Sun rotates?
The Sun rotates on its axis every 27 days, the proof for this is that this rotation was observed by taking notice of the sunspots. This is why you see the sun moving in the clouds, sometimes it's bright and other times it's not.
(K) What is Ohm's law?
Ohm's Law is a formula used to calculate the relationship between voltage, current and resistance in an electrical circuit.
(I) Why is deforestation a threat to biodiversity?
Deforestation can lead directly to biodiversity loss. This is because the animals which live in the trees will loose their home and start to die out, eventually causing extinction. Deforestation can also lead to extinction of a species of trees, causing biodiversity loss to the environment.
(K) Which of the following is not an ionic compound?
a) NaBr
b) Lif
c) S8
S8 is not an ionic compound
(T, I, A) Do other planets have seasons?
Yes, other planets can have seasons some of them have very obvious ones and others seasonal change isn't too noticeable.
(K) What unit is electrical energy measured in?
electrical energy is measured in Watts.
(K, A) Why do dominant species have to be primary producers?
Dominant species have to be primary species because, there are so many of them so, it wouldn't make sense for them to be secondary or tertiary consumers.
(K,T, I) Describe the most simplest molecular compounds.
The most simplest molecular compounds are made up of 2 or more atoms of different elements. These elements are usually non-metals.
(K, I) What is the Big Bang theory?
The big bang theory is that the universe started at a single point and, gradually expanded and stretched.
( A, K) Describe the factors that contribute to the environmental costs of burning fossil fuels to generate electricity.
Fossil fuel power plants burn coal or oil to create heat which is in turn used to generate steam to drive turbines which generate electricity. These plants generate electricity reliably over long periods of time, and are generally cheap to build.