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प्रश्न
State the modern periodic law.
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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?
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?
What is meant by a group, in a periodic table?
What is meant by a period, in a periodic table?
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?
Which of the following statement is correct in regard to the classification of elements?
(a) Elements in modern periodic table are arranged on the basis of increasing atomic masses.
(b) Elements in Mendeleev's periodic table are arranged on the basis of increasing atomic numbers.
(c) In modern periodic table, the element nickel of lower atomic mass is kept before the element cobalt of higher atomic mass.
(d) In modern periodic table, the isotopes of chlorine having different atomic masses are kept in the same group.
Which of the following statement about the modern periodic table is correct?
(a) It has 18 horizontal rows known as periods.
(b) It has 7 vertical columns known as periods.
(c) It has 18 vertical columns known as groups.
(d) It has 7 horizontal rows known as groups.
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same period of the periodic table?
Consider the following elements:
Ca, Cl, Na, I, Li, Ba, Sr, K, Br
Separate these elements into three groups (families) of similar properties. State one property in each case on the basis of which you have made your choice.
What is the number of valence electrons in the atoms of first elements in a period?
What is the major characteristic of the first elements in the periods of the periodic table? What is the general name of such elements?
Explain why, the first period of the periodic table has only two elements whereas second period has eight elements
Helium and neon are unreactive gases. What, if anything, do their atoms have in common?
Name the metals in the first twenty elements.
The electronic configuration of an element T is 2, 8, 8, 1.
What is the period number of T?
State the modern periodic law for classification of elements. How many (i) groups and (ii) periods are there in the modern periodic table?
What is meant in the periodic table by a period?
What is the number of elements in the 1st period?
Give the symbol and valency of the following element and radical.
Hydrogen
Give the symbol and valency of the following element and radical.
Chlorine [Chloride]
Give the symbol and valency of the following element and radical.
Sulphur [Sulphide]
Give the symbol and valency of the following element and radical.
Nitrogen [Nitride]
Give the symbol and valency of the following element and radical.
Bisulphite
Give the chemical formula of sodium bicarbonate
State what the group number in the Modern Periodic Table signifies. Give a reason why elements in the same group, have similar valency and similar chemical properties.
State the number of elements in Period 2 of the Periodic Table.
Compare Modern Periodic Law with Mendeleev's Periodic Law.
Group 1 and 2 : s block : : group 13 and 18 : _______
The modern periodic table shows the molecular masses of the elements in each frame.
The K and L shells of the elements Na and Mg contain electrons.
Complete the following flow chart.
Noble gases belong to______ group of the periodic table.
______ is the longest period in the periodical table.
The scientist who propounded the modern periodic law is ______.
Identify gas A in the following experiment.
The element which has the least tendency to lose electrons is ______
On moving from left to right in a period in the periodic table, the size of the atom ______
The longest period of the Modern Periodic Table is period.
What is the symbol of the element Tungsten?
Which of the following elements will form an acidic oxide?
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?
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.
An element ‘M' has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of ‘M’ is ______.
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?
