Advertisements
Advertisements
Question
What are the atomic numbers of elements whose outermost electrons is represented by 2p3.
Advertisements
Solution
2p3
Completing the electron configuration of the element as
1s2 2s2 2p3.
∴ Number of electrons present in the atom of the element = 2 + 2 + 3 = 7
∴ Atomic number of the element = 7
APPEARS IN
RELATED QUESTIONS
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 | |
Explain the Mass number with example.
What are the atomic numbers of elements whose outermost electrons is represented by 3s1.
Fill in the blanks.
Isotopes are the atoms of ______ element having the ______ atomic number but ______ mass number.
Write true or false for the following statement
An atom on the whole has a positive charge.
Multiple Choice Questions
The sub atomic particle with negative charge is
Multiple Choice Questions
If the atomic number of an atom is 17 and mass number is 35 then number of neutron will be
Fill in the blanks- The number of protons in the nucleus of an atom is called its ....................
(a) What is meant by (i) atomic number, and (ii) mass number, of an element? Explain with the help of an example.
(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?
Draw the orbital diagram of `""_20^40"Ca"^(2+)` ion and state the number of three fundamental particles present in it.
Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one:
- Forms an anion
- Forms a cation
- Has four electrons in its valence shell?
Match the statements in List I with the correct answer from List II.
| List I | List II |
| 1. Mass number of an atom is the number of protons and | A: Electron |
| 2. The sub-atomic particle with a negligible mass. | B: Argon |
| 3. An atom having stable electronic configuration. | C: Nitrogen |
| 4. A molecule formed by sharing of electrons [covalency] | D: Sodium |
| 5. A metallic atom having unstable electronic configuration. | E: Neutrons |
The diagram represents an isotope of hydrogen [H]. Answer the following:
Atomic no. = 1
Mass no. = 1
Do isotopes have the same atomic number or the same mass number?
Define the term of atomic number.
Differentiate mass number from atomic number.
The elementary particles such as protons and neutrons are collectively called ______.
Mass No. 27 is for the element ______.
What are the letters A, Z, and X stand for?
If M is the atomic mass and A is the mass number, then packing fraction is given by ______.
State the term for the following:
The amount of substance which contains the same number of units as the number of atoms in carbon-12.
