Free Discovery of the Proton MCQs with Answers

• A. the cathode of the discharge tube
• B. the residual gas atoms losing electrons in a discharge tube
• C. the radioactive decay of uranium
• D. the anode metal evaporating

Explanation: Goldstein observed that cathode rays travelling through a perforated cathode knocked electrons off the residual gas atoms, leaving…

• A. cathode rays
• B. positive rays produced in a discharge tube with a perforated cathode
• C. radioactive decay of uranium
• D. the photoelectric effect

Explanation: Goldstein observed rays travelling towards the cathode and passing through holes in it, and the lightest positive particles, obtained when…

• A. positive rays are electromagnetic waves
• B. the positive ions formed are the ionised atoms of that particular gas
• C. positive rays travel faster
• D. the cathode is perforated

Explanation: Positive rays are the residue of atoms that have lost electrons, so their mass differs from gas to gas, whereas cathode rays are electrons…

• A. Electron
• B. Proton
• C. Neutron
• D. None of These

Explanation: The electron carries one negative elementary charge, while the proton carries an equal positive charge and the neutron has no charge.

• A. Shell
• B. Nucleus
• C. Energy levels
• D. Orbit

Explanation: The nucleus contains protons and neutrons, which account for almost all of an atom's mass; the electrons in the shells have extremely…

• A. Anode Rays
• B. Cathode Rays
• C. Canal Rays
• D. Gamma Rays

Explanation: Cathode rays are streams of electrons emitted from the cathode, so they carry negative charge.

• A. Electron
• B. Proton
• C. Neutron
• D. All have mass

Explanation: A neutron is slightly heavier than a proton, with a mass of about 1.675 x 10^-27 kg compared with about 1.673 x 10^-27 kg for a proton…

• A. arrangement of electrons in orbitals
• B. position in the periodic table
• C. properties depend upon mass
• D. chemical properties

Explanation: Isotopes are atoms of the same element with the same atomic number but different mass numbers, because they contain different numbers of…

• A. Mass
• B. e/m ratio
• C. Isotopes
• D. None of These

Explanation: A mass spectrometer separates ions according to their mass-to-charge ratio, m/z, by combining electric and magnetic fields.

• A. Shell
• B. Orbit
• C. Nucleus
• D. Orbital

Explanation: Nearly all an atom's mass is concentrated in its nucleus because it contains the relatively heavy protons and neutrons, whereas electrons…

• A. +ve
• B. -ve
• C. Neutral
• D. None of them

Explanation: A positron is the antimatter counterpart of the electron, so it has the same mass as an electron but a positive charge.

• A. Cathode rays
• B. Canal rays
• C. X-rays
• D. Alpha rays

Explanation: Canal rays, also called positive rays, consist of positively charged ions and were observed by Eugen Goldstein.

• A. Proton and neutron
• B. Neutron and electron
• C. Proton
• D. Neutron

Explanation: Every atomic nucleus contains protons, and the number of protons defines the element’s atomic number.

• A. 10 disintegration per second
• B. 1.5 disintegration per second
• C. 0.01 disintegration per second
• D. 1 disintegration per second

Explanation: The becquerel is the SI unit of activity, defined as one nuclear disintegration per second: 1 Bq = 1 disintegration s^-1.

• A. Beta particle
• B. Gamma particle
• C. Alpha particle
• D. Negative particle

Explanation: An alpha particle is a helium-4 nucleus containing two protons and two neutrons, so its net charge is +2e.

• A. Radio elements
• B. Active elements
• C. Radioactive elements
• D. Nuclear elements

Explanation: Elements that spontaneously emit alpha, beta or gamma radiation from unstable nuclei are called radioactive elements.

• A. e
• B. 2e
• C. 3e
• D. 4e

Explanation: An alpha particle is a helium nucleus with two protons, and each proton contributes a charge of +e, giving a total charge of +2e.

• A. Gold foils
• B. Barium sulphate
• C. Zinc sulphide screen
• D. Thin Aluminium sheet

Explanation: Alpha particles produce flashes of light when they strike a zinc sulphide screen, allowing their paths or impacts to be detected.

• A. Fast neutrons
• B. Slow neutrons
• C. Moderate neutrons
• D. All are possible

Explanation: Neutron speed is related to its kinetic energy, and a neutron with energy in the MeV range is classified as a fast neutron.

• A. Attractive forces
• B. Repulsive force
• C. Electrons
• D. Neutrons

Explanation: In the classical model of an atom, the outward centrifugal effect associated with an electron’s circular motion is balanced by the inward…