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प्रश्न
Rearrange the columns 2 and 3 so as to match with the column 1.
| Column 1 | Column 2 | Column 3 |
| i. Triad | a. Lightest and negatively charged particle in all the atoms | 1. Mendeleev |
| ii. Octave | b. Concentrated mass and positive charge | 2. Thomson |
| iii. Atomic number | c. Average of the first and the third atomic mass | 3. Newlands |
| iv. Period | d. Properties of the eighth element similar to the first | 4. Rutherford |
| v. Nucleus | e. Positive charge on the nucleus | 5. Dobereiner |
| vi. Electron | f. Sequential change in molecular formulae | 6. Moseley |
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उत्तर
|
Column I
|
Column II
|
Column III
|
| i. Triad | c. Average of the first and the third atomic mass | 5. Dobereiner |
| ii. Octave | d. Properties of the eight-element similar to the first. | 3. Newlands |
| iii. Atomic Number | e. Positive charge on the nucleus. | 6. Moseley |
| iv. Period | f. Sequential change in molecular formulae | 1. Mendeleev |
| v. Nucleus | b. Concentrated mass and positive charge | 4. Rutherford |
| vi. Electron | a. Lightest and negatively charged particle in all the atoms | 2. Thomson |
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संबंधित प्रश्न
Rewrite the following statement after correction, if necessary:
Groups have elements with consecutive atomic numbers.
An element Y is in second period and group 16 of the periodic table:
(i) Is it a metal or non-metal?
(ii) What is the number of valence electrons in its atom?
(iii) What is its valency?
(iv) What is the name of the element?
(v) What will be the formula of the compound formed by Y with sodium?
A metal X is in the first group of the periodic table. What will be the formula of its oxide?
The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):
-
1 18 a 2 13 14 15 16 17 b c d e
(i) Select the letter which represents an alkali metal.
(ii) Select the letter which represents a nobles gas.
(iii) Select the letter which represents a halogen.
(iv) What type of bond is formed between a and e?
(v) What type of bond is formed between d and e?
The elements A, B and C belong to groups 1, 14, and 17 respectively of the periodic table.
(a) Which two elements will form a covalent compound?
(b) Which two elements will form an ionic compound?
Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electron shells but different number of electrons in their outermost shells. It was found that elements A and G combine to form an ionic compound. This ionic compound is added in a small amount to almost all vegetables and dishes during cooking. Oxides of elements A and B are basis in nature while those of elements E and F acidic. The oxide of element D is, however, almost neutral. Based on the above information, answer the following questions:
(a) To which group or period of the periodic table do these elements belong?
(b) What would be the nature of compound formed by a combination of elements B and F?
(c) Which two of these elements could definitely be metals?
(d) Which one of the eight elements is most likely to be found in gaseous state at room temperature?
(e) If the number of electrons in the outermost shell of elements C and G be 3 and 7 respectively, write formula of the compound formed by the combination of C and G.
(a) How is possible valency of an element determined from the electronic configuration of its atom ?
(b) Determine the valency of an element X whose atomic number is 15.
What was the basis of the earliest attempts made for classification and grouping of elements?
Match the following
| 1. | Galvanisation | Noble gas elements |
| 2. | Calcination | Coating with Zn |
| 3. | Redox reaction | Silver-tin amalgam |
| 4. | Dental filling | Alumino thermic process |
| 5. | Group 18 elements | Heating in the absence of air |
Moseley’s periodic table is based on atomic mass.
An atom of an element has the electronic configuration 2,8,2. To which group does it belong?
An element X combines with oxygen to form an oxide XO. This oxide is electrically conducting. Write the formula of the compound formed when X reacts with chlorine.
The elements of group 16 are called ______
An element with the atomic number 40 is placed in the period.
Arrange the following elements in the order of their decreasing metallic character
Na, Si, Cl, Mg, Al
Identify and name the metals out of the following elements whose electronic configurations are given below.
- 2, 8, 2
- 2, 8, 1
- 2, 8, 7
- 2, 1
An element X of group 15 exists as diatomic molecule and combines with hydrogen at 773 K in presence of the catalyst to form a compound, ammonia which has a characteristic pungent smell.
- Identify the element X. How many valence electrons does it have?
- Draw the electron dot structure of the diatomic molecule of X. What type of bond is formed in it?
- Draw the electron dot structure for ammonia and what type of bond is formed in it?
Complete the following triads by inserting the missing elements.
Li, ______, K
How are elements grouped into various families in the periodic table?
