Advertisements
Advertisements
प्रश्न
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
19K, 3Li, 11Na, 4Be Which of these atoms has smallest atomic radius?
Advertisements
उत्तर
19K, 3Li, 11Na, 4Be
Electronic configuration of the following elements is:
19K = 2,8,8,1
3Li = 2,1
11Na = 2,8,1
4Be = 2,2
4Be has smallest atomic radius because 19K, 3Li, 11Na are present in same group 1 but Be is present in group 2. According to the trend, as we move from left to right atomic size of an atoms decreases. Due to large positive charge on the nucleus, the electrons are pulled closer to the nucleus and the size of atom decreases.
APPEARS IN
संबंधित प्रश्न
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
4Be, 6C, 8O, 5B, 13Al Which is the most electropositive element among these?
Write the scientific reason.
The third period contains only eight elements even though the electron capacity of the third shell is 18
An element has its electron configuration as 2,8,2. Now answer the following questions.
i. What is the atomic number of this element?
ii. What is the valency of this element?
iii. What is the group of this element?
iv. To which period does this element belong?
v. With which of the following elements would this element resemble?
`_7N , _4Be , _18Ar , _17CL`
Which of this element belong to the period 3? Write their electronic configuration
`3^(Li) , 14^(Si) , 2^(He) , 15^(P)`
An element has its electron configuration as 2, 8, 2. Now answer the following question.
What is the atomic number of this element?
An element has its electron configuration as 2, 8, 2. Now answer the following question.
To which period does this element belong?
Find the odd one out and give its explanation.
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.
Highest electropositive element
Beryllium and calcium are alkaline earth metals.
Write a scientific reason.
Boron and oxygen elements are placed in the second period in periodic table.
Find the period in which these elements can be placed.
4Be, 17Cl, 2He, 13Al
Electronic configuration of element A is 2,8,1. Answer the following questions based on this information.
- What is the atomic number of element A?
- Find the group to which this element belongs.
Write name of elements, symbol, atomic number, electronic configuration of second period in modern periodic table?
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?
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.
Make a chart which shows the name of the element, valency, atomic number, electronic configuration in the 2nd row of the modern periodic table and arrange these elements in ascending order of atomic mass.
