More Chemistry Tips & Exam Strategies

Periodic Table

(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:

  1. Elements are arranged in the order of increasing proton / atomic number
  2. A horizontal row of elements is called a Period
  3. A vertical column of elements is called a Group
  4. Elements are further divided into Metals & Non-Metals (Green line in the above image)
  5. 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!

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