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प्रश्न
Which of the following have inert gases 2 electrons in the outermost shell.
पर्याय
He
Ne
Ar
Kr
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उत्तर
He
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संबंधित प्रश्न
Write the electronic configuration of two elements X and Y whose atomic numbers are 20 and 17 respectively. Write the molecular formula of the compound formed when element X reacts with element Y. Draw the electron-dot structure of the product and also state the nature of the bond formed between both the elements.
State whether the following statement is true of false:
The elements in a group have consecutive atomic numbers.
Rewrite the following statement after correction, if necessary:
Isotopes are the elements of the same group.
The element which forms a basis oxide has the atomic number of:
(a) 18
(b) 17
(c) 14
(d) 19
An element A has an atomic number of 6. Another element B has 17 electrons in its one neutral atom.
(a) In which groups of the periodic table would you expect to find these elements?
(b) what type of bond is formed between A and B?
(c) Suggest a formula of the compound formed between A and B.
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 |
Among the given species A–, A+, and A, the smallest one in size is ______.
Element ‘A’ has electronic configuration 2, 7; ‘B’ has electronic configuration 2, 8, 5 and ‘C’ has electronic configuration 2, 8, 7. Which two elements will exhibit similar chemical properties?
Relate the names of the following scientists with the statements given below.
Arranged elements into groups containing three elements each.
Element 'X' forms an oxide with the formula X2O3 which is a solid with high melting point. ‘X’ would most likely be placed in the group of the Periodic Table as:
