The element that has 3 protons is Lithium. In the periodic table, each element is defined by the number of protons in its nucleus, which is also referred to as its atomic number. For Lithium, the atomic number is 3, meaning it contains three protons. This property categorizes Lithium as an alkali metal, which is located in group 1 of the periodic table.
Lithium is a lightweight metal and is primarily used in batteries, particularly in rechargeable lithium-ion batteries. Its unique properties, including its low density and high electrochemical potential, make it a key element in various technological applications.