* Alkali Metals: These are the elements in Group 1 of the periodic table. They are known for having one valence electron.

* Protons: The number of protons in an atom's nucleus determines its atomic number.

Let's look at the first few alkali metals:

* Lithium (Li): Atomic number 3 (3 protons)

* Sodium (Na): Atomic number 11 (11 protons)

* Potassium (K): Atomic number 19 (19 protons)

Answer: The alkali metal with fewer than 10 protons in the nucleus is Lithium (Li).