Advertisements
Advertisements
Question
Write the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
Advertisements
Solution
- The current periodic table consists of seven horizontal rows, known as periods. Periodic elements are ordered in increasing order of atomic numbers. The third row consists of 8 elements, with an electron capacity of 18.
- During the third period, the atomic number and number of electrons in the shell rise as you move left to right. The number of elements in the third period is determined by electronic configuration and the octet rule.
Argon (Ar) is the final element of the third period with a maximum capacity of 18 electrons. The octet of electrons is full, and because argon belongs to the zero group, the third shell has 18 electrons.Atomic No. 11 12 13 14 15 16 17 18 Elements Na Mg Al Si P S Cl Ar
APPEARS IN
RELATED QUESTIONS
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
1H, 7N, 20Ca, 16S, 4Be, 18Ar Which of these elements belong to the second group?
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
7N, 6C, 8O, 5B, 13Al Which is the most electronegative element among these?
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
11Na, 15P, 17Cl, 14Si, 12Mg Which of these has largest atoms?
An element has its electron configuration as 2, 8, 2. Now answer the following question.
To which period does this element belong?
_______ is the outermost shell for elements of period 2.
Which pair of atomic numbers represents elements in the same group?
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Match the columns.
| Column A | Column B |
| 1) s -block | a) Lanthanides and actinides |
| 2) p -block | b) Group 3 to 12 |
| 3) d -block | c) Group 1, 2 |
| 4) f -block | d) Group 13 to 18 |
| e) Zero group |
Match the columns.
| Column A | Column B |
| Electronic configuration |
Valency |
| 1) 2, 2 | a) 1 |
| 2) 2, 8, 1 | b) 2 |
| 3) 2, 5 | c) 3 |
| d) 5 |
Match the columns.
| Column A | Column B |
| 1) Alkaline earth metals | a) Group 18 |
| 2) Alkali metals | b) Group 17 |
| 3) Halogen | c) Group 2 |
| 4) Noble gas | d) Group 1 |
| e) Group 14 |
Write the name.
The element having stable electron configuration from the third period.
The elements lithium and beryllium are in the same period because their valencies are similar.
Beryllium and calcium are alkaline earth metals.
In group 2, beryllium and calcium elements, calcium is more electropositive element than beryllium.
Find the period in which these elements can be placed.
4Be, 17Cl, 2He, 13Al
Observe the given chart and answer the questions given below.
| Element | A | B | C | D |
| Electronic configuration | 2, 1 | 2, 8 | 2, 8, 1 | 2, 8, 8 |
- Which elements are in the same row?
- Which elements have the same column?
- Which elements are in the 18th column?
- Which element is more reactive among A and C?
- Which of the following elements A or B will form compounds?
XY compound is formed by X (Atomic number 11) and Y (Atomic number 17), then answer the questions given below.
- Determine the position of the element X and Y periodic table.
- X and Y belongs to which of the following: metals, nonmetals or metalloids?
- From which block the elements X and Y are?
- Determine the electronic configuration and valency of these elements.
Observe the periodic table given below and write the answers of the questions.
- Write the name and valencies of the elements in 3rd row.
- Classify the elements in this row as metal, nonmetal and metalloids.
- Which block does nonmetals belong to?
- Write name of any two metalloid elements.
