Question

Compare size of lithium (atomic number=3) and boron ( atomic number=5) which one is larger and which one is smaller

Answer 1

Answer: the atomic number of lithium is 3, which indicates that its core charge is +3; the atomic number of boron is 5, which indicates that its nuclear charge is +5. Thus, it is obvious that the charge of the nucleus of a boron atom is higher than the charge of the nucleus of a lithium atom, which means that the electrons in the atoms of the elements will be more strongly attracted by the nucleus of boron. Then, on the whole, the entire electron shell will be pulled closer to the nucleus stronger at the boron, and the radius of the boron atom will be less than the radius of the lithium atom.