Question

What is an Atom? What is the size of Atoms?​

Answer 1

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An atom is the smallest unit of ordinary matter that forms a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across....

The atomic radius of a chemical element is a measure of the size of its atoms. It represents the mean distance from the nucleus to the boundary of the surrounding cloud of electrons....

The size of an atom is defined by the edge of its orbital. ... The units for atomic radii are picometers, equal to 10−12 meters. As an example, the internuclear distance between the two hydrogen atoms in an H2 molecule is measured to be 74 pm. Therefore, the atomic radius of a hydrogen atom is 742=37 pm 74 2 = 37 pm .....

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Answer 2

Answer:

Under most definitions the radii of isolated neutral atoms range between 30 and 300 pm (trillionths of a meter), or between 0.3 and 3 ångströms. Therefore, the radius of an atom is more than 10,000 times the radius of its nucleus (1–10 fm), and less than 1/1000 of the wavelength of visible light (400–700 nm).