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प्रश्न
Right or wrong sentence.
The modern periodic table shows the molecular masses of the elements in each frame.
पर्याय
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
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?
Give two example of group 1 elements.
Name the scientist who prepared modern periodic table.
How does the chemical reactivity of the halogens vary on going in group 17 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?
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 are the periods in a periodic table? Give two characteristics of each.
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)
The following diagram shows a part of the periodic table in which the elements are arranged according to their atomic numbers. (The letters given here not the chemical symbols of the elements):
| a 3 |
b 4 |
c 5 |
d 6 |
e 7 |
f 8 |
g 9 |
h 10 |
|
| i 11 |
j 12 |
k 13 |
l 14 |
m 15 |
n 16 |
o 17 |
p 18 |
(i) Which element has a bigger atom, a or f?
(ii) Which element has a higher valency, k or o?
(iii) Which element is more metallic i or k?
(iv) Which element is more non-metallic, d or g?
(v) Select a latter which represents a metal of valency 2.
(vi) Select a letter which represents a non-metal of valency 2.
Give the group number of following elements present in periodic table
Correct the statement.
Transition elements are placed at extreme right of the periodic table.
Name the type of elements which have outermost shell complete.
Name the type of elements which have two outermost shell incomplete.
What is the main characteristic of the last element in each period of the periodic table?
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
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 the number of elements in the 1st period?
What is the number of elements in the 3rd period, of the modern periodic table?
Name and state the following with reference to the elements of the first three periods of the periodic table.
A covalent compound formed by an element in period 2 and a halogen.
The horizontal rows in a periodic table are called _____.
Name the cation and the anion in the salt – calcium sulphate
Give the symbol and valency of the following element and radical.
Oxygen [Oxide]
Give the symbol and valency of the following element and radical.
Carbonate
Give the chemical formula of sodium sulphite
Give the chemical formula of carbonic acid
State the number of elements in Period 1 of the Periodic Table.
p-block is composed of groups 1 and 2.
Write a scientific reason.
There was ambiguity about the correct position of hydrogen in Mendeleev’s periodic table.
Write a scientific reason.
Lithium and sodium are included in the same group in the periodic table.
Elements in the modern periodic table are arranged in ______groups and______ periods.
______ is the longest period in the periodical table.
On moving from left to right in a period in the periodic table, the size of the atom ______
Where would you locate the element with electronic configuration 2,8 in the Modern Periodic Table?
Noble gases are placed in the ______ group in the modern periodic table.
Answer the following in respect of element \[\ce{_16^32S}\].
To which group and period does it belong?
