The correct chronological sequence is (iv), (ii), (iii), then (i). In 1808, Dalton modeled atoms as indivisible building blocks. In 1897, Thomson proposed the plum pudding model featuring embedded electrons. In 1911, Rutherford established that atoms contain a dense positive central nucleus. FinallyRead more
The correct chronological sequence is (iv), (ii), (iii), then (i). In 1808, Dalton modeled atoms as indivisible building blocks. In 1897, Thomson proposed the plum pudding model featuring embedded electrons. In 1911, Rutherford established that atoms contain a dense positive central nucleus. Finally, in 1913, Bohr proposed that electrons revolve within stable, fixed energy shells without radiating energy.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
Rutherford concluded that the positive charge and nearly all the mass of the atom are concentrated in an extremely small, dense region located at the center, known as the nucleus. Because only a tiny fraction of positively charged alpha particles rebounded or suffered large deflections, this centralRead more
Rutherford concluded that the positive charge and nearly all the mass of the atom are concentrated in an extremely small, dense region located at the center, known as the nucleus. Because only a tiny fraction of positively charged alpha particles rebounded or suffered large deflections, this central nucleus must be very small compared to the total volume and intensely positively charged.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
Statement (iii) is correct because Bohr postulated that electrons revolve in designated orbits called stationary states where they do not radiate energy, maintaining atomic stability. Statement (i) is incorrect because non-radiating orbits prevent electrons from falling into the nucleus. StatementsRead more
Statement (iii) is correct because Bohr postulated that electrons revolve in designated orbits called stationary states where they do not radiate energy, maintaining atomic stability. Statement (i) is incorrect because non-radiating orbits prevent electrons from falling into the nucleus. Statements (ii) and (iv) are incorrect because electrons have strictly quantized energies and can only occupy specific allowed shells, never arbitrary spaces between them.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
Statements (ii) and (iii) are correct because alpha particle deflections proved positive charge and atomic mass are concentrated in a tiny central nucleus, replacing Thomson's plum pudding model. Statement (i) is incorrect because James Chadwick discovered neutrons much later in 1932. Statement (iv)Read more
Statements (ii) and (iii) are correct because alpha particle deflections proved positive charge and atomic mass are concentrated in a tiny central nucleus, replacing Thomson’s plum pudding model. Statement (i) is incorrect because James Chadwick discovered neutrons much later in 1932. Statement (iv) is incorrect because alpha deflections were caused by nuclear electrostatic repulsion, not by the motion of revolving electrons.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
Initially, the tone is filled with energetic anticipation and fierce competitive excitement as athletes prepare for the sprint. When the youngest runner falls, the tone turns somber and sympathetic, reflecting anguish and shattered dreams. However, once the other eight runners return to help him, thRead more
Initially, the tone is filled with energetic anticipation and fierce competitive excitement as athletes prepare for the sprint. When the youngest runner falls, the tone turns somber and sympathetic, reflecting anguish and shattered dreams. However, once the other eight runners return to help him, the tone transforms into profound warmth, admiration and joyful celebration of human kindness, concluding on an uplifting note.
For more NCERT Solutions of Class 9 English Kaveri Chapter 5 Nine Gold Medals Question Answer (2026-27)
Explain and arrange the following statements in the correct chronological order to show how atomic models have evolved over time. (i) Bohr’s model proposed that electrons move in fixed orbits around the nucleus, each with a definite energy. (ii) Thomson’s model depicted the atom as a ‘plum pudding’ with electrons embedded in a sphere of positive charge. (iii) Rutherford’s model proposed that atoms have a dense central nucleus. (iv) Dalton’s model described atoms as indivisible particles.
The correct chronological sequence is (iv), (ii), (iii), then (i). In 1808, Dalton modeled atoms as indivisible building blocks. In 1897, Thomson proposed the plum pudding model featuring embedded electrons. In 1911, Rutherford established that atoms contain a dense positive central nucleus. FinallyRead more
The correct chronological sequence is (iv), (ii), (iii), then (i). In 1808, Dalton modeled atoms as indivisible building blocks. In 1897, Thomson proposed the plum pudding model featuring embedded electrons. In 1911, Rutherford established that atoms contain a dense positive central nucleus. Finally, in 1913, Bohr proposed that electrons revolve within stable, fixed energy shells without radiating energy.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-8/
See lessWhat conclusion did Rutherford draw about the position and characteristics of the atom’s positively charged part based on the few alpha particles that bounced back or were deflected at large angles in the gold foil experiment?
Rutherford concluded that the positive charge and nearly all the mass of the atom are concentrated in an extremely small, dense region located at the center, known as the nucleus. Because only a tiny fraction of positively charged alpha particles rebounded or suffered large deflections, this centralRead more
Rutherford concluded that the positive charge and nearly all the mass of the atom are concentrated in an extremely small, dense region located at the center, known as the nucleus. Because only a tiny fraction of positively charged alpha particles rebounded or suffered large deflections, this central nucleus must be very small compared to the total volume and intensely positively charged.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-8/
See lessWhich of the following statements are correct or incorrect according to the Bohr’s atomic model? Give a reason for each statement. (i) Electrons lose energy while moving in fixed orbits and slowly fall into the nucleus. (ii) Electrons can exist anywhere around the nucleus with no fixed energy. (iii) Electrons revolve around the nucleus in orbits of fixed energy without losing energy. (iv) Electrons can be found between energy levels as they move around the nucleus.
Statement (iii) is correct because Bohr postulated that electrons revolve in designated orbits called stationary states where they do not radiate energy, maintaining atomic stability. Statement (i) is incorrect because non-radiating orbits prevent electrons from falling into the nucleus. StatementsRead more
Statement (iii) is correct because Bohr postulated that electrons revolve in designated orbits called stationary states where they do not radiate energy, maintaining atomic stability. Statement (i) is incorrect because non-radiating orbits prevent electrons from falling into the nucleus. Statements (ii) and (iv) are incorrect because electrons have strictly quantized energies and can only occupy specific allowed shells, never arbitrary spaces between them.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-8/
See lessChoose the correct options and explain the reason for the correct and incorrect options in the context of Ernest Rutherford’s gold foil experiment: (i) The experiment clearly showed the existence of neutrons in the nucleus. (ii) The results disproved the plum pudding model and led to the idea of a nucleus at the centre of the atom. (iii) The large deflection of a few alpha particles indicated that most of the mass of the atom and positive charge are packed into a tiny centre. (iv) The way alpha particles were deflected showed that electrons move around the nucleus.
Statements (ii) and (iii) are correct because alpha particle deflections proved positive charge and atomic mass are concentrated in a tiny central nucleus, replacing Thomson's plum pudding model. Statement (i) is incorrect because James Chadwick discovered neutrons much later in 1932. Statement (iv)Read more
Statements (ii) and (iii) are correct because alpha particle deflections proved positive charge and atomic mass are concentrated in a tiny central nucleus, replacing Thomson’s plum pudding model. Statement (i) is incorrect because James Chadwick discovered neutrons much later in 1932. Statement (iv) is incorrect because alpha deflections were caused by nuclear electrostatic repulsion, not by the motion of revolving electrons.
For more NCERT Solutions of Class 9 Science Exploration Chapter 8 Journey Inside the Atom Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-8/
See lessHow does the poet’s tone change from the beginning to the end of the poem?
Initially, the tone is filled with energetic anticipation and fierce competitive excitement as athletes prepare for the sprint. When the youngest runner falls, the tone turns somber and sympathetic, reflecting anguish and shattered dreams. However, once the other eight runners return to help him, thRead more
Initially, the tone is filled with energetic anticipation and fierce competitive excitement as athletes prepare for the sprint. When the youngest runner falls, the tone turns somber and sympathetic, reflecting anguish and shattered dreams. However, once the other eight runners return to help him, the tone transforms into profound warmth, admiration and joyful celebration of human kindness, concluding on an uplifting note.
For more NCERT Solutions of Class 9 English Kaveri Chapter 5 Nine Gold Medals Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/english/kaveri-chapter-5/
See less