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प्रश्न
\[\ce{^24_12Mg}\] and \[\ce{^26_12Mg}\] are symbols of isotopes of magnesium.
(a) Compare the atoms of these isotopes with respect to :
i. the composition of their nuclei
ii. their electronic configurations
(b) Give reasons why the two isotopes of magnesium have different mass numbers.
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उत्तर
(a) i.
|
|
\[\ce{^24_12Mg}\] |
\[\ce{^26_12Mg}\] |
|
|
|
|
|
No. of electrons |
12 |
12 |
|
No. of protons |
12 |
12 |
|
No. of neutrons |
24 - 12 = 12 |
26 - 12 = 14 |
Hence, the composition of nuclei
\[\ce{_12Mg^24->(P,n),(12+12)_12Mg^26->(p,n)(12+14)}\]
ii. Electronic configuration = 2, 8, 2
(b) Mass numbers of two isotopes of magnesium are different because of the different number of neutrons, i.e. 12 and 14, respectively.
संबंधित प्रश्न
Five atoms are labelled from A to E.
| Atoms | Mass No. | Atomic No. |
| A | 40 | 20 |
| B | 19 | 9 |
| C | 7 | 3 |
| D | 16 | 8 |
| E | 14 | 7 |
(a) Which one of these atoms:
(i) contains 7 protons,
(ii) has an electronic configuration 2, 7?
(b) Write down the formula of the compound formed between C and D.
(c) predict which are: (i) metals, (ii) non-metals?
What type of bond is formed between two atoms, when the electronegative difference between them is low ?
Match the column A with Column B.
|
Column A |
Column B |
|
(i) Sodium chloride (ii) Ammonium ion (iii) Carbon tetrachloride |
Covalent bond Ionic bond Covalent and coordinate bond |
Explain fractional atomic mass. What is the fractional mass of chlorine?
Draw orbit structure diagram of sodium chloride (NaCl).
Identify the following reaction as either oxidation or reduction:
K - e- → K+
The element that would form anion by gaining electrons in a chemical reaction is ______.
What is meant by a chemical bond?
Complete the following table:
| Atoms | Atomic number | Electron distribution | |
| 1. | O | 8 | ______ |
| 2. | N | ______ | ______ |
| 3. | ______ | 17 | ______ |
| 4. | ______ | ______ | 2,8,2 |
Elements A, B and C have atomic number 17, 19 and 10 respectively.
Write down the formula of the compound formed by two of the above elements.
