Today, i will be sharing with you a question on Chemical Bonding found in Pass With Distinction – Chemistry (Topical) book. I wrote this book since year 2011 for Shinglee Publisher Pte Ltd and it contains thought-provoking application questions based on the latest basic Chemistry syllabus.
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(You can find the book locally in Popular Bookstores. For overseas, you can get the autographed copy directly from us.)
Let’s us take a look at the question.
Question:
The elements T, X and Y have consecutive, increasing atomic numbers. If element X is a noble gas, what will be the chemical formula of the compound formed between T and Y?
A. T2Y
B. YT2
C. TY
D. YT
Now, go take out a piece of paper and work on the question before you scroll down to look at the suggested solution.
Suggested Solution:
Step 1: Find out the Group Numbers of element T, X and Y
Element X should be from Group O since it is a noble gas.
Since elements T, X and Y have consecutive, increasing atomic numbers, therefore element T must be from Group VII and element Y must be from Group I.
Step 2: Determine if ionic / covalent compound is formed
Element T is a Group VII non-metal while element Y is a Group I metal.
As such, they will form an ionic compound.
Step 3: Determine the formula of the compound formed
Element Y will lose one electron from its valence shell to form Y+ ion.
Element T will gain one electron from its valence shell to form T– ion.
As such, the formula will be YT and answer will be (D).
Note:
By convention, formula of ionic compounds is usually displayed with positive ion on the left. Thus answer is not (C).
I am sure you learned something useful today.
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tnks.i really gain