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प्रश्न
In the modern periodic table, the positions of 1 to 20 elements are shown here. Identify the elements A and B. Write their atomic number.
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उत्तर
- Element A is lithium (Li).
Element B is neon (Ne). - Atomic number of element A is 3.
Atomic number of element B is 10.
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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?
Why do all the elements of the same group have similar properties?
Fill in the following blank with suitable word:
Group 1 elements are called ...............
State how the valency of elements varies in a group of the periodic table?
(b) What is the number of elements is 3rd period, the modern periodic table?
Helium and neon are unreactive gases. What, if anything, do their atoms have in common?
State the term
The tabular arrangement of elements in horizontal rows and vertical columns _________
Name the scientist who stated the modern periodic law.
Correct the statement.
Transition elements are placed at extreme right of the periodic table.
Name two elements in each case:
Transition element
Name the type of elements which have outermost shell complete.
Name the noble gas with 3 shells.
State the main aim of classifying elements. Which is the more fundamental property of elements that is used in the development of Modern Periodic Table? Name and state the law based on this fundamental property. On which side of the periodic table one can find metals, non-metals and metalloids?
What is meant in the periodic table by a period?
Give the symbol and valency of the following element and radical.
Sodium
Give the symbol and valency of the following element and radical.
Nitrogen [Nitride]
Give the symbol and valency of the following element and radical.
Ammonium
Give the symbol and valency of the following element and radical.
Nitrate
Give the chemical formula of sodium sulphite
Answer the following question in one sentence.
The modern periodic table is divided into which blocks?
Write a 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.
______ is the longest period in the periodical table.
Which of these belong to the same period?
| Element | A | B | C |
| Atomic number | 2 | 10 | 5 |
The amount of energy released when one or more electrons is added to the neutral atom is ______
The longest period of the Modern Periodic Table is period.
The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belong to the same group?
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
Compare the radii of two species X and Y. Give reasons for your answer.
- X has 12 protons and 12 electrons
- Y has 12 protons and 10 electrons
Arrange the following elements in the increasing order of their metallic character
| Mg, | Ca, | K, | Ge, | Ga |
Group 16 elements are collectively called as ______.
Define groups of modern periodic table.
An element with atomic number ______ will form a basic oxide.
An element has 2 electrons in its N shell.
State its position in periodic table.
Answer the following in respect of element \[\ce{_16^32S}\].
Give its formula with hydrogen.
Match the atomic number with the following:
An element of group 2.
