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प्रश्न
Which one of the following does not increase while moving down the group of the periodic table?
विकल्प
Atomic radius
Metallic character
Valency
Number of shells
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उत्तर
Valency
संबंधित प्रश्न
Fill in the blank:
The formulae of chloride of metal M is MCl2. The metal M belongs to ……………. group.
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 elements Be, Mg and Ca each having two electrons in their outermost shells are in periods 2, 3, and 4 respectively of the modern periodic table. Answer the following questions, giving justification in each case:-
(i) Write the group to which these elements belong.
(ii) Name the least reactive element.
(iii) Name the element having largest atomic radius.
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.
Two elements ‘A’ and ‘B’ belong to the 3rd period of Modern periodic table and are in group 2 and 13, respectively. Compare their following characteristics in tabular form:-
(a) Number of electrons in their atoms
(b) Size of their atoms
(c) Their tendencies to lose electrons
(d) The formula of their oxides
(e) Their metallic character
(f) The formula of their chlorides
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.
The electrons in the atoms of four elements A, B, C and D are distributed in three shells having 1, 3, 5 and 7 electrons in the outermost shell respectively. State the period in which these elements can be placed in the modern periodic table. Write the electronic configuration of the atoms of A and D and the molecular formula of the compound formed when A and D combine.
Based on the group valency of elements state the formula lot the following giving justification for each :-
(i) Oxides of 1st group elements,
(ii) Halides of the elements of group 13, and
(iii) Compounds formed when an element of group 2 combines with, an element of group 16.
Which element has the electronic configuration 2, 8, 2?
Arrange the following elements in the increasing order of their metallic character:
Mg, Ca, K, Ga
How does the electropositive character of elements change on going down in a group of the periodic table?
How does the tendency to lose electrons change as we go down in group 1 of the periodic table? Why does it change this way?
In terms of electronic configurations, explain the variation in the size of the atoms of the elements belonging to the same period and same group ?
The atomic number of an element is 20. In modern periodic table, this element is placed:
(a) 2nd period
(b) 4th period
(c) 3rd period
(d) 1st period
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
Name two elements you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
An element X belong to 4th period and 17th group, state.
name of the element.
An element X belong to 4th period and 17th group, state.
name the family to which it belong.
Name the element of lower nuclear charge out of Be and Mg.
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.
An element 'X' (Atomic number – 20) burns in the presence of oxygen to form a basic oxide.
(a) Identify the element and write its electronic configuration.
(b) State its group number and period number in the Modern Periodic Table.
(c) Write a balanced chemical equation for the reaction when this oxide is dissolved in water.
On the basis of electronic configuration, how will you identify the first and the last element of a period?
How many groups and periods are there in the modern periodic table?
Fill in the blank
There are ______ groups and ______ periods in the modern form of periodic table.
Explain
Size of atom changes when it loses or gain electron
Select the correct answer
Number of shells in potassium are
Copy and complete the following sentence choosing the correct word or words from those given below, at the end of the sentence:
The similarities in the properties of elements belonging to a group are because they have the same ______
What is meant by a group in the periodic table?
Give the number of the group and the period of elements having three shells with three electrons in valence shell.
In the above table, H does not represent hydrogen.Some elements are given in their own symbol and position in the periodic table while others are shown with a letter. With refrence to the table answer the following questions.
1. Identify the most electronegative element.
2. Identify the most reactive element of Group I.
3. Identify the element from Period 3 with least atomic size.
4. How many valence electrons are present in Q?
5. Which element from group 2 would have the least ionisation energy?
6. Identify the noble gas of the fourth period.
7. In the compound between A and H, what type of bond would be formed and give its molecular formula.
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 type of ion will be formed by elements A, B, and C.
Moving left to right in the second period, the number of valence electrons _____.
An element A has 2 electrons in its fourth shell. State:
is it a metal or non-metal
Based on the group valency of element write the molecular formula of the following compound giving justification:
Oxide of first group elements.
Name the elements in Period 1.
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 _______.
Name or state following with reference to the element of the first three periods of the periodic table.
The valency of elements in group 1 [I–A].
Name or state following with reference to the element of the first three periods of the periodic table.
The valency of the element in period 3 having atomic number 17.
Which of the following would weigh the least?
(Atomic masses C = 12, 0 = 16, Na = 23)
Match the option A and B with the statements (i) and (ii):
| A. metal | (i) The metal that forms two types of ion. |
| B. iron | (ii) An element with electronic configuration 2, 8, 8, 3. |
