Talking about Chemistry: English Vocabulary List

a tabular arrangement of chemical elements organized based on their atomic number, electron configuration, and recurring chemical properties

"The periodic table organizes chemical elements."

"The periodic table organizes all known chemical elements into rows and columns based on their atomic number and similar chemical properties."

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

"Carbon has an isotope."

"Scientists use a rare isotope of carbon to determine the age of ancient fossils and artifacts."

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

"Chlorine is a halogen."

"The halogen group on the periodic table includes elements like chlorine and fluorine that are highly reactive and are often used in disinfectants and toothpaste."

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

"Helium is a noble gas."

"Noble gases are the elements in the far right column of the periodic table that are very stable and rarely react with other elements under normal conditions."

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

"The half-life is ten years."

"The biological half-life of a toxin in an organism can be far longer than its radioactive half-life"

the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei in radioactive substances

"Radioactivity can be very dangerous."

"Radioactivity is the process by which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves."

a type of uranium that has most of its more radioactive isotopes removed, primarily used for armor-piercing ammunition and shielding

"Depleted uranium is very dense."

"Depleted uranium is a very dense metal that is sometimes used to make armor-piercing ammunition because of its high density and ability to penetrate heavy armor."