10th Standard Personal Introduction Quiz

Subatomic Particles

• Protons are positively charged ions, while electrons are negatively charged ions.
• Neutrons carry no charge and are considered neutral particles.
• Subatomic particles are components found within an atom.

Discovery of Subatomic Particles

• The proton was discovered by Eugene Goldstein.
• JJ Thomson identified the electron as a fundamental particle.
• James Chadwick is credited with the discovery of the neutron.

Cathode Rays

• Cathode rays consist of electrons and are produced through discharge tube experiments.
• They travel in straight lines and possess mass, demonstrating particle-like properties.

Atomic Structure

• The atomic number (Z) indicates the number of protons in an atom.
• The mass number (A) is the total of protons and neutrons in an atom.
• In a neutral atom, the number of protons equals the number of electrons.
• The number of neutrons can be calculated by subtracting the atomic number from the mass number (A-Z).

Hydrogen Isotopes

• Hydrogen has three isotopes: protium, deuterium, and tritium.
• Isotopes have the same atomic number but differing masses, while isobars share the same mass number but different atomic numbers.

Bohr's Model of the Atom

• According to Bohr's model, electrons orbit the nucleus in fixed paths known as energy shells.
• Each electron shell has a defined energy level, leading to the term "fixed energy levels."
• The energy of an electron increases as its distance from the nucleus increases.