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atomic number

[uh-tom-ik nuhm-ber] / əˈtɒm ɪk ˈnʌm bər /


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Science: Carbon is atomic number 6 on the Periodic Table of Elements.

From The Wall Street Journal ● Oct. 14, 2025

Lighter elements -- generally those with an atomic number of 20 or lower on the periodic table -- often have an equal number of protons and neutrons.

From Science Daily ● Feb. 26, 2024

Katie Hafner: Uranium is the last of the naturally occurring elements on the periodic table, with an atomic number of 92.

From Scientific American ● Sep. 7, 2023

For in truth, how does it really benefit most of us to know why sodium’s atomic number is 11 and magnesium’s 12?

From Washington Post ● Apr. 28, 2023

The horizontal rows, meanwhile, arrange the chemicals in ascending order by the number of protons in their nuclei–what is known as their atomic number.

From "A Short History of Nearly Everything" by Bill Bryson


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