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प्रश्न
The modern periodic table shows the molecular masses of the elements in each frame.
विकल्प
Right
Wrong
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उत्तर
The modern periodic table shows the molecular masses of the elements in each frame- Wrong
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संबंधित प्रश्न
In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21, and 38. Which of these have physical and chemical properties resembling calcium?
Give two example of group 18 elements.
Explain why, the noble gases are placed in a separate group.
Would you place the two isotopes of chlorine, CI-35 and CI-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
The three elements having chemical symbols of Si, B and Ge are:
(a) all metals
(b) all non-metals
(c) all metalloids
(d) Si is metalloid, B is metal and Ge is non-metal
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:
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.
How does the chemical reactivity of the halogens vary on going in group 17 of the periodic table?
On the basis of electronic configuration, how will you identify the first element of a period?
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.
Name the scientist who stated the modern periodic law.
Correct the statement.
Copper and zinc are representative elements.
Name two elements in halogens.
Name the type of elements which have outermost shell incomplete.
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.
What would be the correct order if Zn, Fe, Al and Cu are arranged in increasing order of reactivity?
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
Give the symbol and valency of the following element and radical.
Nitrogen [Nitride]
Give the symbol and valency of the following element and radical.
Bisulphate
Give the symbol and valency of the following element and radical.
Bisulphite
Give the chemical formula of magnesium nitrate
State the number of elements in Period 1 of the Periodic Table.
What are the periods in a periodic table?
To the left of the zig-zag line in the periodic table are the metal elements.
Position of A, B and C three elements is given in the table from the modern periodic table. Answer the following questions.
| Periods | Group 2 | Group 17 |
| 2 | ----- | A |
| 3 | B | ----- |
| 4 | ----- | C |
- What is A element metal or nonmetal?
- Which is the outermost orbit of element B?
- Identify C element and it's physical state.
Which of these belong to the same period?
| Element | A | B | C |
| Atomic number | 2 | 10 | 5 |
On moving from left to right in a period in the periodic table, the size of the atom ______
Which of the following is the outermost shell for elements of period 2?
Which of the following elements does not lose an electron easily?
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?
The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively. The mass of Y is approximately equal to the average mass of X and Z. What is such an arrangement of elements called as? Give one example of such a set of elements.
“Hydrogen occupies a unique position in Modern Periodic Table”. Justify the statement.
Spot the error:
The elements of group 13 are called the carbon family.
A part of modern periodic table is given below. On its basis, answer the following questions:
| Group No. → | 1 | 2 | 13 | 14 | 15 | 16 | 17 | 18 |
| Period ↓ | ||||||||
| 2 | A | B | ||||||
| 3 | E | D | F | C |
Which of the element is a Metalloid?
What is the general name of the last elements of the Periodic Table?
Name the following metal:
A metal present in period 3, group 1 of the periodic table.
