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प्रश्न
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उत्तर
Atomic size increases down the group
- The atomic numbers of the elements increase as we go down the group. Thus, the elements placed lower have more electrons.
- To accommodate these electrons new shells are added to the atom.
- These new shells take the outermost electrons farther from the nucleus causing atomic size (radius) to increase as we go down the group.
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संबंधित प्रश्न
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.
Name the element that has two shells, both of which are completely filled with electrons.
Classify the following elements into metals, non-metals and metalliods
As, C, Hg, Mg, S, Si
An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is ______.
Calculate the mass of Calcium that will contain the same number of the atom as are present in 3.2 gm of Sulphur.
[Atomic masses: S=32, Ca=40]
Rewrite the following statement after correction, if necessary:
Elements in the same period have equal valency
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.
How does the electropositive character of elements change on going down in a group of the periodic table?
State one reason for keeping fluorine and chlorine in the same of the periodic table.
In which part of a group would you separately expect the elements to have the largest atomic size?
The electronic configuration of the atom of an element X is 2, 8, 4. In modern periodic table, the element X is places in :
(a) 2nd group
(b) 4th group
(c) 14th group
(d) 8th group
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
Which one of the following does not increase while moving down the group of the periodic table?
In each of the following pair, choose the atom having the bigger size:
(a) Mg (At. No.12) or Cl (At. No.17)
Periodicity is observed due to the similar ______.
Correct the statements.
Elements in the same periods have equal valency.
An element has 2 electrons in its N shell.
State the name assigned to this group.
State the valency of the elements of periods 3 and write the formula of their oxides.
An element X belong to 3rd periods and group II of the periodic table state:
the number of valence electrons,
An element 'M' has atomic number 12.
(a) Write its electronic configuration.
(b) State the group to which 'M' belongs.
(c) Is 'M' a metal or a non-metal.
(d) Write the formula of its chloride.
What is modern periodic law?
What is meant by periodicity of elements?
Fill in the blank
Most electropositive elements belong to ______ group.
How could the atomic radius of a noble gas be compared with the other elements in a period?
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.
An element Z has atomic number 16. Answer the following
(a) State the period and group to which Z belongs
(b) Is Z a metal or a non-metal?
(c) State the formula between Z and hydrogen.
(d) what kind of a compund is this?
Arrange the following as per the instruction given in the bracket
He,Ar,Ne (Increasing order of the number of electron shells)
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.
An element belongs to the third period and Group IIIA (13) of the periodic table. State: the number of valence electrons,
An element belongs to the third period and Group IIIA (13) of the periodic table. State: the valency,
Going across a period left to right, atomic size _____.
An element A has 2 electrons in its fourth shell. State:
is it an oxidising or reducing agent
The electronic configuration of an element is 2, 8, 4. State it:
group and period in the Modern Periodic Table.
Based on the group valency of element write the molecular formula of the following compound giving justification:
Oxide of first group elements.
Based on the group valency of element write the molecular formula of the following compound giving justification:
Compound formed when an element A of group 2 combines with an element B of group seventeen.
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 non-metallic element present in period 3 other than sulphur and chlorine.
Electron Affinity is maximum in ______.
