a tabular arrangement of chemical elements organized based on their atomic number, electron configuration, and recurring chemical properties
周期表
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, leading to variation in atomic mass
同位体
a type of chemical element found in Group 17 of the periodic table, known for being highly reactive and commonly used in disinfectants and lights
ハロゲン
any of the elements in Group 18 of the periodic table, including helium, neon, argon, krypton, xenon, and radon, characterized by their inert nature and stable electron configurations
希ガス
a mixture of two liquids where tiny droplets of one are evenly dispersed in the other, like oil in water
エマルジョン
the time required for half of a quantity of a substance to undergo a change or decay, typically in the context of radioactive decay or chemical reactions
半減期
the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei in radioactive substances
放射能
a type of uranium that has most of its more radioactive isotopes removed, primarily used for armor-piercing ammunition and shielding
減耗ウラン