Answer:
Step-by-step explanation:
The atomic radius of an element is a measure of the size of its atoms. It is defined as half the distance between the nuclei of two adjacent atoms in a crystal lattice of the element.
In the case of boron and carbon, we observe that boron has a larger atomic radius (87 pm) than carbon (67 pm). This is contrary to what we would expect based on their positions in the periodic table. Boron is located to the left of carbon and has one less proton in its nucleus, which would suggest that it should have a smaller atomic radius than carbon.
However, other factors can influence the atomic radius of an element, such as the effective nuclear charge experienced by the outermost electrons. The effective nuclear charge is the net positive charge experienced by an electron in an atom, taking into account the shielding effect of inner-shell electrons.
In the case of boron, it has one less electron than carbon, so the effective nuclear charge experienced by the outermost electron is greater. This causes the electron to be attracted more strongly to the nucleus, making the atom smaller. In contrast, the larger number of electrons in the carbon atom results in weaker attraction to the nucleus and a larger atomic radius.
In summary, the observation that boron has a larger atomic radius than carbon can be explained by considering the effective nuclear charge experienced by the outermost electrons in each atom.