Lightest element is

🔑 Key Points
🧪 Hydrogen (H2)
→ H2 is the chemical formula of hydrogen.
→ Hydrogen is the lightest element in nature on Earth.
→ It contains only one proton.
→ It has zero neutrons.
→ Hydrogen has the lowest mass compared to other elements.
→ The atomic number of a Hydrogen atom is 1.

📝 Additional Information
🪐 Helium (He)
→ He is the chemical formula of the helium element.
→ Helium is the 2nd lightest element on Earth.
→ It is a noble gas element.
→ It has the atomic number 2.
→ Helium has 2 neutrons, 2 protons, and 2 electrons.

🌬️ Argon (Ar)
→ Ar is the chemical formula of the argon element.
→ Argon is a noble gas element.
→ It belongs to group 18 of the periodic table.
→ It has the atomic number 18.
→ Argon is the 3rd most abundant gas on Earth's surface.

⚡ Lithium (Li)
→ Li is the chemical formula of the lithium element.
→ Lithium is the 3rd lightest element.
→ It is an alkali metal and has the lightest weight among alkali metals.
→ Lithium has 3 protons, 3 electrons, and 4 neutrons.