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प्रश्न
Right or wrong sentence.
The modern periodic table shows the molecular masses of the elements in each frame.
विकल्प
Right
Wrong
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उत्तर
The given sentence is wrong.
Explanation:
The modern periodic table shows each element’s atomic number (and often its atomic/relative atomic mass) in the cell; it does not show a “molecular mass”. Elements have atomic masses; “molecular mass” refers to compounds (molecules).
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संबंधित प्रश्न
How does the metallic character of elements in Modern Periodic Table vary on moving from left to right in a period, and (ii) down a group?Give reason to justify your answer.
How does the tendency of elements to gain electrons change as we move from left to right in a period? State the reason of this change.
Name the scientist who first of all showed that atomic number of an element is a more fundamental property than its atomic mass.
State modern periodic law.
What is meant by a group, in a periodic table?
Is it possible to have an element having atomic number 1.5 placed between hydrogen and helium?
The modern periodic table was prepared by ______.
How would the tendency to gain electrons change on moving from left to right in a period of the periodic table?
How does the chemical reactivity of alkali metals vary on going in group 1 of the periodic table?
What is the major characteristic of the first elements in the periods of the periodic table? What is the general name of such elements?
State how the valency of elements varies in a group of the periodic table?
State how the valency of elements varies in a period of the periodic table?
Helium and neon are unreactive gases. What, if anything, do their atoms have in common?
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.
Give the group number of following elements present in periodic table
Name the scientist who stated the modern periodic law.
Name two elements in halogens.
What do you understand by typical elements?
Name the type of elements which have outermost shell complete.
Name the type of elements which have two outermost shell incomplete.
How does the electronic configuration of an atom relate to its position in the modern periodic table?
The electronic configuration of an element T is 2, 8, 8, 1.
- What is the group number of T?
- What is the period number of T?
- How many valence electrons are there in an atom of T?
- What is the valency of T?
- Is it a metal or a non-metal?
State the modern periodic law for the classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
What is the number of elements in the 1st period?
Two elements P and Q belong to the same period of the modern periodic table and are in group 1 and group 2, respectively. Compare the following characteristics in the tabular form.
- Number of electrons in their atoms
- Their tendency to lose electrons
- Their metallic characters
- Formation of their oxides
- Formulae of their chlorides
Define the atomic size.
Give the chemical formula of carbonic acid
Find the correlation:
Group 1 and 2 : s block : : group 13 and 18 : ______
Find the odd one out and give its explanation.
Write a scientific reason.
There was ambiguity about the correct position of hydrogen in Mendeleev’s periodic table.
An X element with atomic number 11 and Y element with atomic number 13 belongs to the third period in the modern periodic table. With this information, give the answers of the below questions.
- Which element has more metallic character from these two elements?
- What is the valency of each X and Y elements?
- Atom size of Y element is smaller than atom size of X element? Explain?
Noble gases belong to______ group of the periodic table.
Where would you locate the element with electronic configuration 2,8 in the Modern Periodic Table?
Explain the position of hydrogen in the periodic table.
Give the criteria on the basis of which elements are placed (i) in a group and (ii) in a period in the modern periodic table. The atomic number of an element is 16. According to the criteria, in which group and period it should be placed?
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?
