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प्रश्न
What are the atomic numbers of elements whose outermost electrons is represented by 3p5?
उत्तर
3p5
Completing the electron configuration of the element as
1s2 2s2 2p6 3s2 3p5
∴ Number of electrons present in the atom of the element = 2 + 2 + 6 + 2 + 5 = 17
∴ Atomic number of the element = 17
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संबंधित प्रश्न
With the help of given Table, find out the mass number of sulphur atom.
| Composition of Atoms of the First Eighteen Elements with Electron Distribution in Various Shells | ||||||||||
| Name of Element | Symbol | Atomic Number | Number of protons | Number of Neutrons | Number of Electrons | Distribution of Electrons | Valency | |||
| K | L | M | N | |||||||
| Hydrogen | H | 1 | 1 | - | 1 | 1 | - | - | - | 1 |
| Helium | He | 2 | 2 | 2 | 2 | 2 | - | - | - | 0 |
| Lithium | Li | 3 | 3 | 4 | 3 | 2 | 1 | - | - | 1 |
| Beryllium | Be | 4 | 4 | 5 | 4 | 2 | 2 | - | - | 2 |
| Boron | B | 5 | 5 | 6 | 5 | 2 | 3 | - | - | 3 |
| Carbon | C | 6 | 6 | 6 | 6 | 2 | 4 | - | - | 4 |
| Nitrogen | N | 7 | 7 | 7 | 7 | 2 | 5 | - | - | 3 |
| Oxygen | O | 8 | 8 | 8 | 8 | 2 | 6 | - | - | 2 |
| Fluorine | F | 9 | 9 | 10 | 9 | 2 | 7 | - | - | 1 |
| Neon | Ne | 10 | 10 | 10 | 10 | 2 | 8 | - | - | 0 |
| Sodium | Na | 11 | 11 | 12 | 11 | 2 | 8 | 1 | - | 1 |
| Magnesium | Mg | 12 | 12 | 12 | 12 | 2 | 8 | 2 | - | 2 |
| Aluminium | Al | 13 | 13 | 14 | 13 | 2 | 8 | 3 | - | 3 |
| Silicon | Si | 14 | 14 | 14 | 14 | 2 | 8 | 4 | - | 4 |
| Phosphorus | P | 15 | 15 | 16 | 15 | 2 | 8 | 5 | - | 3.5 |
| Sulphur | S | 16 | 16 | 16 | 16 | 2 | 8 | 6 | - | 2 |
| Chlorine | Cl | 17 | 17 | 18 | 17 | 2 | 8 | 7 | - | 1 |
| Argon | Ar | 18 | 18 | 22 | 18 | 2 | 8 | 8 | 0 | |
State the mass number, the atomic number, number of neutrons and electronic configuration of the following atoms.
`""^12""_6C, ""^16""_8O, ""^19""_9F, ""^20""_10Ne, ""_13""Al""^27, ""_17""Cl""^35`
Also, draw atomic diagrams for them.
Tick the most appropriate answer.
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- isobars
- elements
- isotopes
- none of these
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All the mass of an atom is concentrated in a small region of space called the ___________.
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(b) What is the relation between the atomic number and mass number of an element?
(c) If an element M has mass number 24 and atomic number 12, how many neutrons does its atom contain?
What is the significance of atomic numbers in the modern Periodic Table?
Sulphur has an atomic number 16 and a mass of 32.
State the number of protons and neutrons in the nucleus of sulphur. Give a simple diagram to show the arrangement of electrons in an atom of sulphur.
From the symbol `""_2^4"He"` for the element helium, write down the mass number and the atomic number of the element.
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What is the (a) atomic number (b) number of protons in this element?
What is meant by the 'atomic number of an element'?
Define the term ‘mass number’ of an atom.
The diagram represents an isotope of hydrogen [H]. Answer the following:
Atomic no. = 1
Mass no. = 1
Are isotopes atoms of the same element or different elements.
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Isotopes of hydrogen [11H, 21H, 31H]
Atomic number : ______ :: Mass number : Number of protons and neutrons.
Show diagrammatically the electron distributions in a sodium atom and a sodium ion and also give their atomic number.
Mass No =______ + No. of Neutrons.
Match the following:
| Column A | Column B | ||
| 1. | Mass of proton | a. | +1 |
| 2. | Mass of electron | b. | -1 |
| 3. | Charge of electron | c. | 9.31 x 10-28g |
| 4. | Charge of proton | d. | 1.67 x 10-24g |
An element has 2 electrons in its N shell.
What is its atomic number?
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:
The atomic number of boron is 5. Write the chemical formula of the compound formed when boron reacts with chlorine.
