The atomic number of an element on the periodic table is the whole number typically found above the element's symbol.
Here's a breakdown:
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What it is: The atomic number represents the number of protons in the nucleus of an atom of that element. It is unique to each element.
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Where to find it: Look at the periodic table. Each element is assigned a box, and within that box, you will find:
- The element's symbol (e.g., H for Hydrogen, He for Helium).
- The element's name (e.g., Hydrogen, Helium).
- The atomic number (a whole number, usually at the top of the box).
- The atomic mass (a decimal number, usually at the bottom of the box).
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Example: As the reference video illustrates, for Argon (Ar), the atomic number is 18. This means every Argon atom has 18 protons in its nucleus.
Therefore, to find the atomic number, simply locate the element on the periodic table and identify the whole number prominently displayed, usually above the element's symbol.
