Atomic size: Lithium has a smaller atomic size than potassium. This is because lithium has a lower atomic number (3) than potassium (19). The atomic number of an element is equal to the number of protons in the nucleus of an atom. The more protons an atom has, the more electrons it will have, and the larger the atom will be.

Ionic radius: Lithium has a smaller ionic radius than potassium. This is because lithium loses one electron to form a positively charged ion (Li+), while potassium loses one electron to form a positively charged ion (K+). The more electrons an atom loses, the smaller the ion will be.

Electronegativity: Lithium has a lower electronegativity than potassium. This means that lithium is less likely to attract electrons from other atoms. Electronegativity is a measure of an atom's ability to attract electrons. The more electronegative an atom is, the more likely it is to attract electrons from other atoms.