Here are the atomic numbers of the first 25 elements in the periodic table:
- Hydrogen - Atomic Number: 1
- Helium - Atomic Number: 2
- Lithium - Atomic Number: 3
- Beryllium - Atomic Number: 4
- Boron - Atomic Number: 5
- Carbon - Atomic Number: 6
- Nitrogen - Atomic Number: 7
- Oxygen - Atomic Number: 8
- Fluorine - Atomic Number: 9
- Neon - Atomic Number: 10
- Sodium - Atomic Number: 11
- Magnesium - Atomic Number: 12
- Aluminum - Atomic Number: 13
- Silicon - Atomic Number: 14
- Phosphorus - Atomic Number: 15
- Sulfur - Atomic Number: 16
- Chlorine - Atomic Number: 17
- Argon - Atomic Number: 18
- Potassium - Atomic Number: 19
- Calcium - Atomic Number: 20
- Scandium - Atomic Number: 21
- Titanium - Atomic Number: 22
- Vanadium - Atomic Number: 23
- Chromium - Atomic Number: 24
- Manganese - Atomic Number: 25
These atomic numbers represent the number of protons in the nucleus of each atom and help define the unique identity of each element.