Why is the radius of a lithium atom larger than the radius of hydrogen atoms
The radius of an atom is determined by the distance from the nucleus to the outermost electron shell. In the case of lithium and hydrogen atoms, lithium has one more electron than hydrogen, therefore, it has more electron shells and a larger atomic radius.
Lithium has three electrons and three electron shells, while hydrogen has only one electron and one electron shell. The electrons in lithium are therefore further away from the nucleus on average, leading to a larger atomic radius compared to hydrogen.
Additionally, the presence of more electrons in lithium also results in increased electron-electron repulsion, which causes the electron cloud to expand further away from the nucleus, contributing to the larger atomic radius of lithium compared to hydrogen.