The term "atomic number 81" refers to an element in the periodic table called "thallium." Let's break this down for a new English learner:
Basic Definition:
Atomic Number 81: This is a scientific term used to identify thallium, which is a soft, grey metal. It can be shaped easily (malleable) and looks a bit like tin, but when it is exposed to air, it changes color (discolors).
Characteristics:
Soft Grey Metal: Thallium is not hard and has a grey color.
Malleable: You can bend or shape it without breaking it.
Highly Toxic: This means it is very dangerous to living things and can be harmful if touched or ingested. It is often used in poisons for killing rodents and insects.
Usage Instructions:
In Chemistry: When studying the periodic table, you will see "Tl" as the symbol for thallium, and it will be found in the section for atomic number 81.
In Context: You might hear about thallium in discussions about chemistry, environmental science, or toxic substances.
Example Sentence:
Advanced Usage:
In more advanced discussions, thallium is often mentioned in the context of its applications in electronics, optics, and medicinal chemistry, particularly in the development of certain types of cancer treatments.
Word Variants:
Different Meanings:
Synonyms:
Idioms and Phrasal Verbs:
Summary:
In summary, "atomic number 81" is a scientific term that specifically identifies the element thallium, a soft, grey metal that is toxic and used in certain poisons.