Name of particle Position in the atom Mass used for practical purpose Proton Nucleus 1u Electron Orbit 0 Neutron Nucleus 1u Is there any relation between the total number of protons and neutrons in an atom and its mass?

The sum of protons and neutrons determines the mass number of an element. The mass number almost equals to the atomic mass of an element. Mass number = Number of protons + Number of electrons

Symbols of certain atoms given in the table. Complete the table. Symbols Atomic Number Mass Number Protons Electrons Neutrons H 1 1 He 2 4 Li 3 7 C 6 12 Ne 10 20 Ar 18 40

An isotope of any element can be uniquely represented as X Z A , where X is the atomic symbol of the element, A is the mass number and Z is the atomic number. The atomic number is equal to the number of protons or electrons, so we can calculate easily. The mass number in a nucleus is the combined number of protons and neutrons. So, subtract atomic number from a mass number we will get a number of neutrons. Symbols Atomic Number Mass Number Protons Electrons Neutrons H 1 1 1 1 1 1 0 He 2 4 2 4 2 2 2 Li 3 7 3 7 3 3 4 C 6 12 6 12 6 6 6 Ne 10 20 10 20 10 10 10 Ar 18 40 18 40 40 40 22

Complete the following table regarding the filling up of electrons in shells. Name of Shells Number of Shells Maximum number of electrons K 1 2 × 1 2 = 2 L 2 2 × 2 2 = 8 M 3 ------- N ---- -------

The maximum number of electrons that can be accommodated in any given shell is 2 n 2 (n= Shell number). Name of Shells Number of Shells Maximum number of electrons K 1 2 × 1 2 = 2 L 2 2 × 2 2 = 8 M 3 2 × 3 2 = 18 N ---- 2 × 4 2 = 32

MEDIUM

9th Kerala Board

IMPORTANT

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Name of particle Position in the atom Mass used for practical purpose

Proton Nucleus 1u

Electron Orbit 0

Neutron Nucleus 1u

Find the mass of an atom having two protons and two neutrons.

Important Questions on Structure of Atom

HARD

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q •

Name of particle	Position in the atom	Mass used for practical purpose
Proton	Nucleus	1u
Electron	Orbit	0
Neutron	Nucleus	1u

Is there any relation between the total number of protons and neutrons in an atom and its mass?

MEDIUM

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q •

Which is the fundamental particle of an atom that can be displaced when atoms rub against each other, or they undergo a chemical reaction with other atoms? Give reasons.

MEDIUM

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q •

If you know the atomic number of an atom the number of which all particles can be found? Give reason.

MEDIUM

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q •

If you know the mass number of an atom the number of which all particles can be found? Give reason.

HARD

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1

Symbols of certain atoms given in the table. Complete the table.

Symbols	Atomic Number	Mass Number	Protons	Electrons	Neutrons
${}_{1}^{1}H$
${}_{2}^{4}{He}$
${}_{3}^{7}{Li}$
${}_{6}^{12}C$
${}_{10}^{20}{Ne}$
${}_{18}^{40}{Ar}$

MEDIUM

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q •

Analyse the electronic configuration of elements from atomic number $1$ to $18$ in the following table;

Question Image

What is the maximum number of electrons that can be accommodated in the K shell?

HARD

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q •

Analyse the electronic configuration of elements from atomic number $1$ to $18$ in the following table;

Question Image

What is the maximum number of electrons that can be accommodated in L shell?

MEDIUM

9th Kerala Board

IMPORTANT

Chemistry Standard IX Part 1>Chapter 1 - Structure of Atom>Exercise 1>Q 1

Complete the following table regarding the filling up of electrons in shells.

Name of Shells	Number of Shells	Maximum number of electrons
K	$1$	$2 \times 1^{2} = 2$
L	$2$	$2 \times 2^{2} = 8$
M	$3$	-------
N	----	-------

Name of particle Position in the atom Mass used for practical purpose Proton Nucleus 1u Electron Orbit 0 Neutron Nucleus 1u Find the mass of an atom having two protons and two neutrons.

Important Questions on Structure of Atom

Learn and Prepare for any exam you want !

Name of particle Position in the atom Mass used for practical purpose

Proton Nucleus 1u

Electron Orbit 0

Neutron Nucleus 1u

Find the mass of an atom having two protons and two neutrons.