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
Given below are some elements of the modern periodic table. Atomic number of the element is given in parentheses.
A(4), B(9), C(14), D(19), E(20)
(a) Select the element that has one electron in the outermost shell. Also, write the electronic configuration of this element.
(b) Which two elements amongst these belong to the same group? Give reasons for your answer.
(c) Which two elements amongst these belong to the same period? Which one of the two has bigger atomic radius?
The atomic numbers of three elements A, B and C are 12, 18 and 20 respectively. State, giving reason, which two elements will show similar properties.
An element 'X' has mass number 35 and number of neutrons 18. Write atomic number and electronic configuration of 'X'. Also write group number, period number and valency of 'X'.
Name the element that has two shells, both of which are completely filled with electrons.
An element Z has atomic number 16. Answer the following questions on Z:
1) State the period and group to which Z belongs
2) Is Z a metal or a non-metal?
3) State the formula between Z and hydrogen
4) What kind of a compound is this?
Arrange the following elements in the increasing order of their metallic character:
Mg, Ca, K, Ga
Fill in the blank in the following statement:
In going across a period (right to left) in periodic table, the atomic size of the atom ...............
The atomic radii of three elements X, Y and Z of a period of the periodic table are 186 pm; 104 pm and 143 pm respectively. Giving a reason, arrange these elements in the increasing order of atomic numbers in the period.
For each of the following triads, name the element with the characteristics specified below:
| Elements | Least atomic radius | Chemically least reactive |
| (i) F, Cl, Br (ii) Li, Na, K |
.................... .................... |
.................... .................... |
How does the atomic size vary on going down from top to bottom in a group of the periodic table? Why does it vary this way?
Where would you locate the element with electronic configuration 2, 8 in the modern periodic table?
Which of the following set of elements is written correctly in the order of their increasing metallic character?
(a) Mg, Al, Si
(b) C, O, N
(c) Na, Li, K
(d) Be, Mg, Ca
Why sodium element of group 1 and chlorine element of group 17 both have valency 1?
What do you understand by orbits?
What is its atomic number?
How does the number of:
valency vary on moving from left to right in the second period of the periodic table?
Fill in the blank:
on moving from right to left in the second period, the number of valence electrons……….
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) ?
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.
Chemical reactivity of elements ?
An element X belong to 3rd periods and group II of the periodic table state:
the number of valence electrons,
Complete the following sentences.
The properties of the elements are a periodic function of their …………… (atomic number, mass number, reative atomic mass).
Name the element in period 3 which does not form oxide.
name the elements in period 1.
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.
Fill in the blank
There are ______ groups and ______ periods in the modern form of periodic table.
Give the number of the group and the period of elements having three shells with three electrons in valence shell.
Choose the most appropriate answer from the following list of oxides which fit the description.
A basic oxide.
Choose the most appropriate answer from the following list of oxides which fit the description.
An amphoteric oxide.
Arrange the following as per instruction given in the bracket.
Mg, Cl, Na, S, Si (decreasing order of atomic size)
Arrange the following as per instruction given in the bracket
Na, K, Cl, S, Si (increasing ionisation potential)
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
|
|
|
|
D |
|
|
B |
C |
|
|
A |
|
|
E |
State which is metals, non-metals, and noble gas in this table.
The position of elements A, B, C, D and E in the periodic table are shown below:
|
Group 1 |
Group 2 |
Group 17 |
Group 18 |
|
|
|
|
D |
|
|
B |
C |
|
|
A |
|
|
E |
State which is most reactive (i) metal (ii) non-metal
An element belongs to the third period and Group IIIA (13) of the periodic table. State: the name of the element.
Moving left to right in the second period, the number of valence electrons _____.
An element A has 2 electrons in its fourth shell. State:
position in the periodic table
Fill in the blank and rewrite the completed statement:
________ group in the periodic table contains elements that are all gases at room temperature.
Answer the following question:
State the four blocks of the modern periodic table based on the electronic configuration of elements.
The position of certain elements in the Modern Periodic Table is shown below:
Using the above table answer the following questions giving reasons in each case :
(i) Which element will form only covalent compounds?
(ii) Which element is a non-metal with valency 2?
(iii) Which element is a metal with valency 2?
(iv) Out of H, C, and F which has the largest atomic size?
(v) To which family does H, C, and F belong?
Name the elements in Period 1.
There are three elements E, F, G with atomic numbers 19, 8 and 17 respectively.
Classify the above elements as metals and non-metals.
