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प्रश्न
Which one of the following does not increase while moving down the group of the periodic table?
पर्याय
Atomic radius
Metallic character
Valency
Number of shells
उत्तर
Valency
संबंधित प्रश्न
Elements in the same group show the same valency. Give scientific reason.
Two elements ‘P’ and ‘Q’ belong to the same period of the modern periodic table and are in Group 1 and Group 2, respectively. Compare their following characteristics in tabular form:-
(a) The number of electrons in their atoms
(b) The sizes of their atoms
(c) Their metallic character
(d) Their tendencies to lose electrons
(e) The formula of their oxides
(f) The formula of their chlorides
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 position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
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'.
How many groups and periods are there in the modern periodic table?
Write the number of periods the Modern Periodic Table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group.
Define the term : Atomic size
Consider two elements 'A' (Atomic number 17) and 'B' (Atomic number 19) :
(i) Write the positions of these elements in the modern periodic table giving justification.
(ii) Write the formula of the compound formed when 'A' combines with 'B.'
(iii) Draw the electron dot structure of the compound and state the nature of the bond formed between the two elements.
In the following set of element, one element does not belong to the set. Select this element and state why it does not belong:
Calcium, Magnesium, Sodium, Beryllium
In the following set of elements, one element does not belong to the set. Select this element and state why it does not belong:
Oxygen, Nitrogen, Carbon, Chlorine, Fluorine
What happens to the metallic character of the elements as we go down in a group 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 valency of elements change of moving from left to right in the third period of the periodic table?
Rewrite the following statement after correction, if necessary:
Elements in the same period have equal valency
Fill in the blank in the following statement:
On moving form right to left in the second period, the number of valency electrons ...............
Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the periodic table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
Why does the size of the atoms progressively become smaller when we move from sodium (Na) to chlorine (Cl) in the third period of the periodic table?
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?
Name two properties of elements whose magnitudes change when going from top to bottom in a group of the periodic table. In what manner do they change?
Which of the following element does not lose an electron easily?
(a) Na
(b) F
(c) Mg
(d) Al
Periodicity is observed due to the similar ______.
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) ?
Name the element in period 3 which does not form oxide.
Name the element of lower nuclear charge out of Be and Mg.
What is the common feature of the electronic configuration of the elements at the end of period 2, and period 3?
What is modern periodic law?
Fill in the blank
Most electropositive elements belong to ______ group.
State the number of elements in period 1, period 2 and period 3 of the periodic table.
Name the elements in period 1.
How many elements are there in period 2?
The following table represents the first period of the modern periodic table. Study the table and answer the questions that follow:
(i) Write the formula of the sulphate of the element with atomic number 13.
(ii) What type of bonding will be present in the oxide of the element with atomic number 1?
(iii) Which feature of the atomic structure accounts for the similarities in the chemical properties of the elements in group VIIA of the periodic table?
(iv) Name the element which has the highest ionization potential.
(v) How many electrons are present in the valence shell of the element with atomic number 18?
(vi) What is the name given to the energy released, when an atom in its isolated gaseous state accepts an electron to form an anion?
(vii) What is the electronic configuration of the element in the third period which gains one electron to become an anion?
(viii) Fill in the blanks:
The atomic size ______ as we move from left to right across the period, because the ______ increases, but the ______ remains the same.
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.
Cs, Na, Li, K, Rb (decreasing electronegativity)
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 |
Place the three elements fluorine, beryllium and nitrogen in the order of increasing electronegativity.
Formula of ion of A is A2+. Element A probably belongs to ______ group.
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 |
Which is larger in size (i) D or E (ii) B or C
Write the electronic configuration of element 17T35.
- What is the group number of T?
- What is the period number of T?
- How many valence electrons are there in an atom of T?
- What is the valency of T?
- Is it a metal or non-metal?
- State number of protons and neutrons in T.
An element belongs to the third period and Group IIIA (13) of the periodic table. State: the number of valence electrons,
State the nature of compounds formed when group 17 elements combine with (i) metals (ii) non-metals.
Name the elements in Period 1.
Name or state following with reference to the element of the first three periods of the periodic table.
A non-metal in period 2 having electronic configuration 2, 6.
Name or state following with reference to the element of the first three periods of the periodic table.
A metal in period 3 having valency 3.
Select the correct answer from the options given below.
Is the group number of the element whose atomic number is 4.
State the following:
The group which contains highly electropositive metals including sodium.
