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प्रश्न
State the modern periodic law.
उत्तर
Modern periodic law states that "The physical and chemical properties of all elements are a periodic function of their atomic numbers".
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संबंधित प्रश्न
Name two elements you would expect to show chemical reactions similar to magnesium. What is the basis for your choice?
How many rows and columns are there in the Modem Periodic Table?
Why do all the elements of the same group have similar properties?
Fill in the following blank with suitable word:
Group 18 elements are called ...............
The atomic numbers of four elements P, Q, R and S are 6, 8, 14 and 16 respectively. Out of these, the element known as metalloid is:
(a) P
(b) Q
(c) R
(d) S
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same group of the periodic table?
State how the valency of elements varies in a group of the periodic table?
What are the groups 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.
The atomic numbers of the three elements X, Y and Z are 2, 6 and 10 respectively.
(i) Which two elements belong to the same group?
(ii) Which two elements belong to the same period?
Give reasons for your choice.
The elements A, B, C and D belong to groups 1, 2, 14 and 17 respectively of the periodic table. Which of the following pairs of elements would produce a covalent bond?
(i) A and D
(ii) C and D
(iii) A and B
(iv) B and C
(v) A and C
Name the scientist who stated the modern periodic law.
Name two elements in Alkaline earth metals.
Name two elements in Inert gas.
Write the number of protons, neutrons and electronic configuration of \[\ce{_19^39K, _15^31P}\]. Also state their position in periodic table.
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.
How will the tendency to gain electrons change as we go from left to right across a period? Why?
Write a short note.
Position of isotopes in the Mendeleev’s and the modern periodic table.
From the standpoint of atomic structure, what determines which elements will be the first and which the last in a period of the periodic table?
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?
How does number of (i) valence electrons (ii) valency; vary on moving from left to right in the second period of a 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.
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Aluminium
Give the symbol and valency of the following element and radical.
Nitrogen [Nitride]
Give the symbol and valency of the following element and radical.
Bicarbonate
Give the symbol and valency of the following element and radical.
Nitrate
Give the symbol and valency of the following element and radical.
Hydroxide
Give the symbol and valency of the following element and radical.
Sulphate
Give the chemical formula of ammonium sulphate
State the number of elements in Period 2 of the Periodic Table.
State the number of elements in Period 3 of the Periodic Table.
How were elements arranged in the long form of the periodic table or the Modern Periodic Table?
The d-block elements are called as _______ elements.
Group 1 and 2 : s block : : group 13 and 18 : _______
The modern periodic table is divided into which blocks?
The modern periodic table has 1 to 7 periods.
The modern periodic table shows the molecular masses of the elements in each frame.
To the left of the zig-zag line in the periodic table are the metal elements.
Write scientific reason.
Lithium and sodium are included in the same group in periodic table.
Noble gases belong to______ group of the periodic table.
______ is the longest period in the periodical table.
______ forms the basis of the modern periodic table.
The scientist who propounded the modern periodic law is ______.
Identify gas A in the following experiment.
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 variable valency and is a member of the Oxygen family (group 16).
Noble gases are placed in the ______ group in the modern periodic table.
Spot the error:
The elements of group 13 are called the carbon family.
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?
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
Answer the following in respect of element \[\ce{_16^32S}\].
Give its formula with hydrogen.
