Tag: science & technology

Alpha particles (alpha rays) are helium nuclei consisting of 2 protons and 2 neutrons, giving them a +2 charge. Beta particles are high-speed electrons with -1 charge. Gamma rays are neutral electromagnetic radiation, and cathode rays are electron beams in vacuum tubes.

Atoms have two main components: electrons that orbit in shells, and a dense central nucleus containing protons and neutrons. Options A, B, and C are incomplete or incorrect because they omit the nucleus or essential particles.

Atomic explosions release energy through nuclear fission, where a small amount of mass is converted to enormous energy according to Einstein's E=mc². Chemical reactions involve electron rearrangement, not mass-energy conversion. Mechanical to nuclear conversion is incorrect, and neutrons don't convert to protons as the primary energy source.

X-rays have wavelengths typically in the range of 0.1 to 10 angstroms (10^-11 to 10^-10 meters), making 1 angstrom the correct order of magnitude. Micron (10^-6 m) is for infrared, centimeter and meter scales are for radio/microwave regions.

Baryons (protons, neutrons) are the heaviest class of hadrons with masses around 938 MeV/c². Mesons (pions, kaons) are intermediate-mass hadrons around 140 MeV/c². Leptons (electrons, neutrinos) are the lightest fundamental particles at 0.511 MeV/c² for electrons. The decreasing mass order is therefore Baryons > Mesons > Leptons.

The visible light spectrum ranges from approximately 3900 to 7600 angstroms (390-760 nanometers), covering violet through red. Options A (8500-9800) and B (7800-8000) are in the infrared range, while D (1300-3000) is in the ultraviolet range.

U-235 is the naturally occurring fissile isotope of uranium capable of sustaining a chain reaction, making up about 0.7% of natural uranium. U-238 (99.3% of natural uranium) is not fissile. U-239 is an unstable decay product of neptunium-239, and U-245 does not exist in nature.