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प्रश्न
Write a short note.
Structure of the modern periodic table.
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उत्तर
Structure of the modern periodic table:
Periodic Table: It is the table of chemical elements arranged in order of atomic number such that elements with similar atomic structure appear in the vertical columns. The Modern periodic law states that The chemical and physical properties of elements are a periodic function of their atomic numbers. The modern periodic table is based on modern periodic law.
Groups: There are 18 vertical columns in the periodic table. Each column is called a group. All elements in a group have similar chemical and physical properties because they have the same number of valence electrons.
Periods: In periodic table elements are arranged in a series of rows. Elements of the same period have the same number of electron shells.
Blocks: The table is divided into four blocks: s-block, p-block, d-block, and f-block, based on the type of orbital being filled. s- and p-blocks are called representative elements, d-block are transition metals, and f-block are inner transition elements (lanthanides and actinides).
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संबंधित प्रश्न
What is periodicity in properties of elements with reference to the Modern Periodic Table?
Give two example of group 18 elements.
What is the name of those elements which divide metals and non-metals in the periodic table?
The three elements having chemical symbols of Si, B and Ge are:
(a) all metals
(b) all non-metals
(c) all metalloids
(d) Si is metalloid, B is metal and Ge is non-metal
State whether the following statement is true or false:
On going down in a group of the periodic table, the number of valence electrons increases.
What is the major characteristic of the first elements in the periods of the periodic table? What is the general name of such elements?
What is the fundamental difference in the electron configurations between the group 1 and group 2 elements?
On the basis of electronic configuration, how will you identify the first element of a period?
What is the main characteristic of the last elements in the periods of the periodic table? What is the general name of such elements?
Which of the following are the correct characteristics of isotopes of an element?
(i) same atomic mass
(ii) same atomic number
(iii) same physical properties
(iv) same chemical properties
(a) (i), (ii) and (iv)
(b) (ii), (iii) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Consider the following elements:
20Ca, 8O, 18Ar, 16S, 4Be, 2He
Which of the above elements would you expect to be:
(i) very stable?
(ii) in group 2 of the periodic table?
(iii) in group 16 of the periodic table?
The elements A, B, C and D belong to groups 1, 2, 14 and 17 respectively of the periodic table. Which of the following pairs of elements would produce a covalent bond?
(i) A and D
(ii) C and D
(iii) A and B
(iv) B and C
(v) A and C
Name two elements in Inert gas.
Name two elements in each case: Lanthanides
What do you understand by typical elements?
Name the metals in the first twenty elements.
An element barium has atomic number 56. Look up its position in the periodic table and answer the following question.
What will be the formula of its phosphate?
Write a short note.
Position of isotopes in the Mendeleev’s and the modern periodic table.
How many periods and groups are there in the modern periodic table?
What is meant in the periodic table by a period?
What is the number of elements in the 1st period?
Name an element of group 18 which can form compounds.
Give the symbol and valency of the following element and radical.
Aluminium
Give the symbol and valency of the following element and radical.
Nitrate
State what is meant by the term chemical formula.
Give the chemical formula of ammonium sulphate
State the number of elements in Period 1 of the Periodic Table.
What are the elements.
The d-block elements are called as _______ elements.
Group 1 and 2 : s block : : group 13 and 18 : _______
Write scientific reason.
There was ambiguity about the correct position of hydrogen in Mendeleev’s periodic table.
State whether true or false. If false, correct the statement.
Lanthanides and actinides are kept at the bottom of the periodic table because they resemble each other but they do not resemble with any other group elements.
Which of the following elements does not lose an electron easily?
Three elements A, B and C have 3, 4 and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the Modern Periodic Table. Also, give their valencies.
The maximum number of electrons that can be accommodated in s, p,d, and f subshells are ______.
Define groups of modern periodic table.
Answer the following in respect of element \[\ce{_16^32S}\].
Give its formula with hydrogen.
Give reason for the following:
Inert gases do not form ion.
