Hi everyone,
One of my GCE O Level Chemistry Sec 4 student from Anglo Chinese School (ACS) sent emailed me a challenging O Level Chemistry Multiple Choice Question (MCQ) and i would like to share it with you.
At first look, it seems to be a very challenging tricky question since you would not know which chapter / topic does the question belongs to. I was contemplating between using essential concepts from either ENERGY CHANGES (Exothermic & Endothermic) or TRENDS IN PERIODIC TABLE to answer the question.
Let’s take a look at the question:
Question 1:
Hi sean, I came across this question and I would like to know the answer.
Which pair of elements, described by their proton number, will react together most exothermically?
A. 1 and 8
B. 3 and 10
C. 9 and 19
D. 12 and 16
Suggested answer and reasoning by my student as follows (i always encourage my student to analyze the question for possible answers and propose it, before asking me for an answer, cos that is how they learn effectively):
I know for sure that B is wrong since proton number 10 is for an unreactive noble gas. My guess is 12 and 16, because both are 2+ and 2-, so the overall charge is greater than the rest.
Which is the correct answer? And on what basis do I use to determine the correct answer?
So all Chemistry students out there (be it GCE O Levels,? GCE A Levels, IGCSE, IB and IP Chemistry), what is your take?
Feel free to give your answers & reasoning in the “LEAVE A REPLY” section below. I would love to hear from you.
PS: I will come in at later stage to give my suggested answer and reasoning [Read more…] about O Level Chemistry Questions: Energy Changes & Periodic Table