Week 1 Homework Answers
Explain how internal and external fertilization both lead to the continuation of a species via different approaches [6 marks]
Video Solution:
Using examples, compare and contrast reversible and irreversible chemical reactions. [4 marks]
Written Solution:
A reversible reaction can proceed in both the forward and reverse direction. Whereas, an irreversible reaction can only proceed in one direction (1 mark). Both can be chemical reactions, evident by signs of a chemical reaction; change in colour, smell, temp.
Irreversible reactions e.g. burning magnesium, 2Mg(s) + O2(g) —> 2MgO(s) (1mark)
Reversible reactions e.g. iron(III) nitrate and potassium thiocyanate
(1 mark)
These reactions are similar since both involve a forward reaction, however, irreversible reactions just lack the reverse reaction. (1 mark)
What forces act on a projectile while it is in motion, draw these in a free body diagram [2 marks]
Assuming gravity is negligible, a single downward force due to gravity should be acting from the centre of the object. Initially, a second F which put the object into motion can also be included.
Math 2 unit: (revision)
HSC 2020, Question 1 MC
D, a square root has a math error if the number inside it is less then 0