More Chemistry Tips & Exam Strategies
(Photo by ma-kasu)
In Chemistry, Periodic Table has long been regarded by students, educators and chemists as the “Bible” of Chemistry.
We need to have a good grasp of the General Features & the important Patterns (Group Trends) in order to appreciate many other topics and to score in exams.
General Features of Periodic Table:
- Elements are arranged in the order of increasing proton / atomic number
- A horizontal row of elements is called a Period
- A vertical column of elements is called a Group
- Elements are further divided into Metals & Non-Metals (Green line in the above image)
- Electronic configurations, period number & group number are related to each other
Example:
Sodium (Na) is located in Group I and Period 3 of the Periodic Table.
Electronic Configurations of Sodium (Na) atom is 2.8.1
This shows that Na atom has only 1 valence (outermost shell) electrons and all the electrons occupies 3 shells (2 electrons occupy innermost shell, 8 electrons occupy 2nd shell and 1 electrons located in the outermost shell).
The above highlight a very important feature of Periodic Table:
Period Number = Number of electron shells
Group Number = Number of outermost electrons
Got it? Let me know if you need any clarifications.
Let’s try out some basic exam-based questions for a start:
Quick Check 1:
How many Groups & Periods are there in the Periodic Table?
A) 9 and 6 respectively
B) 9 and 7 respectively
C) 8 and 6 respectively
D) 8 and 7 respectively
Quick Check 2:
How many elements are found in the 1st Period of the Periodic Table?
A) 8
B) 6
C) 2
D) 1
Try it out!
PS: Leave your answers in the comments section below. We will get back to you with our suggested answer too!
thera are 18 groups in the periodic table and 2 elements in period 1
WHY WE CALL WAX VAPOUR AND NOT// A GASSEOUS VAPOUR
Hi farhan,
Discussions on SimpleChemConcepts.com is based on Basic Chemistry Syllabus (such as GCE-O Levels Chemistry).
For elements that can hold more than 8 electrons in their outermost shell, they belong to Advanced Level Chemistry (such as GCE-A Levels Chemistry). Do visit the new webiste for advanced level chemistry students : http://www.ALevelH2Chemistry.com to find more discussions.
To Your Academic Success in Chemistry,
Sean Chua
Master Trainer & Author
Hi Kim,
The rectangular block of metal elements between Group II and III is known as Transition Metals and NO group number are assigned to them. As such, there should only be 8 Groups in the Periodic Table.
For Quick Check 2, you are absolutely right. Well Done.
To Your Academic Success in Chemistry,
Sean Chua
Master Trainer & Author
Hi Kerk Yan Juin,
Response to your suggested answers.
Quick Check 1:
– Spot on. Answer is indeed D. Well Done!
Quick Check 2:
– Common error! You had fall into the trap set by many examiners and teachers.
– Look again at 1st Period which is the Horizontal Row – there are only H and He there.
As such, answer should be C.
To Your Academic Success in Chemistry,
Sean Chua
Master Trainer & Author
You can do so by checking the topic you think is most challenging and then click “vote”.
Rgds,
Sean Chua
how to find group and period for a element having more than 8 electrons in its outermost shell?
i wish to participate in chemistry vote
Don’t the metals count? I see 18 vertical columns, puzzled by the lack of an explanation for that.
Plus the first period has only two elements, hydrogen and helium. So the answer is C
Quick Check 1:
There are 8 Groups(Vertical Column) and 7 Periods(Horizontal Column)
in the Periodic Table.
Hence the answer is D.
Quick Check 2:
There are 6 elements found in the 1st Period(Horizontal Column)
of the Periodic Table.
Hence, the answer is B.