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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?
Fill in the following blank with suitable word:
The basis for modern periodic table is ...............
What is meant by a period, in a periodic table?
How many periods and groups are there in the long form of periodic table?
Give two example of group 1 elements.
where should hydrogen be placed in the modern periodic table? Give reason for your answer.
What is the name of those elements which divide metals and non-metals in the periodic table?
Would you place the two isotopes of chlorine, CI-35 and CI-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
Consider the following elements:
Ca, Cl, Na, I, Li, Ba, Sr, K, Br
Separate these elements into three groups (families) of similar properties. State one property in each case on the basis of which you have made your choice.
On the basis of electronic configuration, how will you identify chemically similar elements?
On the basis of electronic configuration, how will you identify the first element of a period?
What is the usual number of valence electrons and valency of group 18 elements of the periodic table?
What is the main characteristic of the last elements in the periods of the periodic table? What is the general name of such elements?
What is a group in the periodic table?
What are the periods in a periodic table? Give two characteristics of each.
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?
Name two elements in each case:
Transition element
Name two elements in each case:
Actinides
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
An element E has following electronic configuration:
|
K |
L |
M |
|
2 |
8 |
6 |
(a) To which group of the periodic table does element E belong?
(b) To which period of the periodic table does element E belong?
(c) State the number of valence electrons present in element E.
(d) State the valency of the element E.
What would be the correct order if Zn, Fe, Al and Cu are arranged in increasing order of reactivity?
Name the cation and the anion in the salt – calcium sulphate
Give the symbol and valency of the following element and radical.
Calcium
Give the symbol and valency of the following element and radical.
Oxygen [Oxide]
Give the symbol and valency of the following element and radical.
Ammonium
Give the symbol and valency of the following element and radical.
Sulphate
Give the chemical formula of sodium hydroxide
Give the chemical formula of carbonic acid
How were elements arranged in the long form of the periodic table or the Modern Periodic Table?
Which of the following statements about the Modern periodic table is correct?
Write a scientific reason.
Lithium and sodium are included in the same group in the periodic table.
Distinguish between:
s-block - p-block
______ forms the basis of the modern periodic table.
Identify gas A in the following experiment.
The element which has the least tendency to lose electrons is ______
The amount of energy released when one or more electrons is added to the neutral atom is ______
An element which is an essential constituent of all organic compounds belongs to
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has same valency as Lithium.
- Write the electronic configuration of element X, given by its symbol as under: \[\ce{^40_20 X}\]
- Determine its position in the modem periodic table.
- What is the nature of its oxide?
- Name one other element of its group.
