How many groups and periods are there in the Modern Periodic Table?
18 groups and 7 periods
Understanding the Modern Periodic Table Structure
The Modern Periodic Table is a fundamental tool in chemistry, organizing all known chemical elements in a structured way. This arrangement helps us understand the properties of elements and predict their behavior. The table is organized into rows and columns, each with specific names: groups and periods.
What are Groups and Periods?
- Groups: These are the vertical columns in the Periodic Table. Elements in the same group generally have similar chemical properties because they have the same number of valence electrons (electrons in the outermost shell).
- Periods: These are the horizontal rows in the Periodic Table. Elements in the same period have the same number of electron shells. As you move across a period from left to right, the atomic number increases by one for each successive element.
Number of Groups and Periods in the Modern Periodic Table
The Modern Periodic Table has a specific number of groups and periods. Let's look at the standard arrangement:
There are 18 vertical columns. These columns are numbered from 1 to 18 from left to right. Each column represents a group.
There are 7 horizontal rows. These rows are numbered from 1 to 7 from top to bottom. Each row represents a period.
The two rows placed separately at the bottom of the table are the Lanthanides and Actinides series. They are actually part of Period 6 and Period 7 respectively, fitting into Group 3.
Analyzing the Options
The question asks for the number of groups and periods in the Modern Periodic Table. Based on our understanding:
- Option 1: 7 groups and 18 periods - Incorrect. The numbers are swapped, and the counts are wrong.
- Option 2: 7 groups and 7 periods - Incorrect. This might confuse the number of periods with the number of groups.
- Option 3: 18 groups and 7 periods - Correct. This matches the standard structure of the Modern Periodic Table.
- Option 4: 18 groups and 18 periods - Incorrect. The number of periods is 7.
Therefore, the Modern Periodic Table contains 18 groups and 7 periods.
| Feature | Description | Quantity |
|---|---|---|
| Groups | Vertical columns | 18 |
| Periods | Horizontal rows | 7 |
Revision Table: Modern Periodic Table Structure
| Feature | Arrangement | Count |
|---|---|---|
| Groups | Vertical Columns | 18 |
| Periods | Horizontal Rows | 7 |
Additional Information: Blocks in the Periodic Table
The Modern Periodic Table can also be divided into four blocks based on the type of atomic orbital that is being filled with electrons:
- s-block: Includes Group 1 (Alkali Metals) and Group 2 (Alkaline Earth Metals), plus Helium.
- p-block: Includes Group 13 to Group 18 (excluding Helium).
- d-block: Includes Group 3 to Group 12 (Transition Metals).
- f-block: Includes the Lanthanides and Actinides series (Inner Transition Metals), usually shown below the main table.
Understanding these blocks helps further explain the properties and electron configurations of elements within the 18 groups and 7 periods.
Important Questions from Chemistry
Common salt (NaCl) is not used as a raw material for preparation of which one of the following compounds?
Which one of the following is the chemical formula of Hypobromous acid?
Which one of the following is not used as a raw material in the manufacture of glass?
Which one of the following statements about dihydrogen (H 2) is not correct?
Reaction of quick lime (CaO) with water to produce slaked lime (Ca(OH) 2) is an example of
