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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
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?
Fill in the following blank with suitable word:
Group 18 elements are called ...............
What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
How were the positions of isotopes of an element decided in the modern periodic table?
where should hydrogen be placed in the modern periodic table? Give reason for your answer.
On which side of the periodic table will you find non-metals?
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
How would the tendency to lose electrons change as we go from left to right across a period of the periodic table?
How do the atomic radii of elements change as we go from left to right in a period of the periodic table?
What is a period in a periodic table?
What happens to the number of valence electrons in the atoms of elements as we go down in a group of the periodic table?
In what respects do the properties of group 1 elements differ from those of group 17 elements? Explain with examples by taking one element from each group.
How many groups and periods does the modern periodic table have?
Name two elements in Alkali metals.
What do you understand by typical elements?
Name the metals in the first twenty elements.
Name the type of elements which have two outermost shell incomplete.
State its position in the periodic table?
Fill in the blank:
The horizontal rows in the periodic table are called _____________.
Give the symbol and valency of the following element and radical.
Sulphur [Sulphide]
Give the chemical formula of sodium sulphite
Right or wrong sentence.
The modern periodic table has 1 to 7 periods.
Right or wrong sentence.
To the left of the zig-zag line in the periodic table are the metal elements.
Write an explanation.
Period
Write a scientific reason.
There was ambiguity about the correct position of hydrogen in Mendeleev’s periodic table.
______ is the longest period in the periodical table.
The scientist who propounded the modern periodic law is ______.
On moving from left to right in a period in the periodic table, the size of the atom ______
Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period?
Which of the following elements will form an acidic oxide?
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.
Explain the position of hydrogen in the periodic table.
An element belonging to 3d series of modern periodic table has spin magnetic moment = 5.92 B.M. in +3 oxidation state. The atomic number of elements are ______.
1H2 is an isotope of hydrogen. In the modern Periodic Table it will ______.
Answer the following in respect of element \[\ce{_16^32S}\].
To which group and period does it belong?
A group of elements in the periodic table is given below (Boron is the first member of the group and Thallium is the last).
Boron, Aluminium, Gallium, Indium, Thallium
Answer the following question in relation to the above group of elements:
If the electronic configuration of aluminium is 2, 8, 3, how many electrons are there in the outer shell of thallium?
