Advertisements
Advertisements
प्रश्न
Taking into consideration the period of the elements given below, answer the following questions:
| Elements | Atomic Radius (pm) |
| O | 66 |
| B | 88 |
| C | 77 |
| N | 74 |
| Be | 111 |
| Li | 152 |
- Arrange the above elements in decreasing order of their atomic radii.
- State the period to which the above elements belong.
- Why this arrangement of elements is similar to the above period of modern periodic table?
- Which of the above elements have the biggest and the smallest atom?
- What is the periodic trend observed in the variation of atomic radius while going from left to right within a period?
Advertisements
उत्तर
- Li > Be > B > C > N > O
- 2nd period
- Yes, this elemental arrangement resembles the era of the contemporary periodic table mentioned above. The positive charge on the nucleus grows one unit at a time as we move from left to right over a period of time, but when electrons are added to the same orbit, the pull away from the nucleus increases, reducing the size of the atom.
- Li is the biggest atom oxygen is the smallest atom
- While going from left to right within a period atomic radius decreases due to an increase in effective nuclear charge.
APPEARS IN
संबंधित प्रश्न
Fill in the blank:
The formulae of chloride of metal M is MCl2. The metal M belongs to ……………. group.
Write the electronic configuration of K and Ne.
Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the modern periodic table and how valency of an element is calculated on the basis of its atomic number.
Calcium is an element with atomic number 20. Stating reason, answer each of the following questions:-
(i) Is calcium a metal or a non-metal?
(ii) Will its atomic radius be larger or smaller than that of potassium with atomic number 19?
(iii) Write the formula of its oxide.
An element 'M' with electronic configuration (2, 8, 2) combines separately with (NO3)–, (SO4)2– and (PO4)3– radicals. Write the formula of the three compounds so formed. To which group and period of the Modern Periodic Table does the element 'M' belong? Will 'M' form covalent or ionic compounds? Give reason to justify your answer.
Write the number of vertical columns in the modern periodic table. What are these columns called?
Consider two elements 'X' (Atomic number 17) and 'Y' (Atomic number 20)
(i) Write the positions of these elements in the modern periodic table giving justification.
(ii) Write the formula of the compound formed by the combination of 'X' and 'Y'.
(iii) Draw the electron-dot structure of the compound formed and state the nature of the bond formed between the two elements ?
Which element has a total of two shells, with three electrons in its valence shell?
Which element has twice as many electrons in its second shell as in its first shell?
How does the number of valence electrons vary on moving from left or right in the first period of the periodic table?
How does the number of valence electrons vary on moving from left or right in the second period of the periodic table?
How does the tendency to gain electrons change as we go down in group 17 of the periodic table? Why does it change this way?
The elements A, B, C, D and E have atomic numbers 9, 11, 17, 12 and 13 respectively. The pair of elements which belongs to the same group of the periodic table is:
(a) A and B
(b) B and D
(c) A and C
(d) D and E
Given alongside is a part of the periodic table. As we move vertically downward from Li to Fr:
| Li | Be |
| Na | |
| K | |
| Rb | |
| Cs | |
| Fr | Ra |
What happens to their metallic character?
An element which is an essential constituent of all organic compounds belongs to following group of modern periodic table:
(a) group 4
(b) group 14
(c) group 15
(d) group 16
The element which has the maximum number of valence electrons is:
(a) Na
(b) P
(c) Si
(d) A
Name two elements you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
How do the following change on moving from left to right in a period of the periodic table?
Give examples in support of your answer.
atomic structure (electron arrangements) ?
Chorine in the periodic table is surrounded by the elements with atomic number 9, 16, 18 and 35.
Which of these have physical and chemical properties resembling chlorine.
Chorine in the periodic table is surrounded by the elements with atomic number 9, 16, 18 and 35.
Which is more electronegative than chlorine?
First ionization enthalpy of two elements X and Y are 500 KJ mol-1 and 375 KJ mol-1 respectively. Comment about their relative position in a group as well as in a period.
On the basis of electronic configuration, how will you identify the first and the last element of a period?
Select the correct answer
Most reactive character among the elements given below is found in
Select the correct answer
Identify the metalloid
How many elements are there in period 2?
Choose the correct answer from the choice given:
An element A belonging to Period 3 and Group II will have
Use the letters only written in the Periodic Table given below to answer the questions that follow:
(a) State the number of valence electrons in the atom J.(b) Which element shown forms ions with a single negative charge?
(c) Which Metallic element is more reactive than R?
(d) Which element has its electrons arranged in four shells?
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
The elements of one short period of the periodic table are given below in order from left to right:
| Li | Be | B | C | O | F | Ne |
Which one of the above elements belongs to the halogen series?
Atomic numbers of elements A, B, C, D, E, F are 8, 7, 11, 12, 13 and 9 respectively. State the type of ions they form.
Name and state the following with reference to the elements of the first three periods of the periodic table.
Metalloid in Period 3.
An element A has 2 electrons in its fourth shell. State:
is it an oxidising or reducing agent
Supply the missing word from those in bracket:
If an element has one electron in its outermost energy level [shell] then it is likely to be _______.
State the property trends in general of elements on moving from left to right in a period of the periodic table.
Name or state following with reference to the elements of the first three periods of the periodic table.
A metalloid in period 2 and in period 3.
Name or state following with reference to the element of the first three periods of the periodic table.
The formula of the hydroxide of the element having electronic configuration 2, 8, 2.
Fill in the blanks from the words A to F given below’.
A: Decreases
B: Increases
C: Remains same
D: Increases by one
E: Electropositive
F: Electronegative
Across a period from left to right in the Modern Periodic Table.
No. of electron shells _________; No. of valence electrons __________: Electronegativity increases Character of elements changes from electropositive to ________.
State the following:
The group to which the element with an electronic configuration of 2, 8, 2 belongs.
