The element that would be expected to behave the most like carbon is silicon. This is because both carbon and silicon belong to Group 14 of the periodic table, which is also known as the carbon group. Elements in the same group share similar chemical properties due to the fact that they have the same number of valence electrons. Both carbon and silicon have four valence electrons, which means that they have a tendency to form covalent bonds with other atoms in order to achieve a stable electron configuration. This similarity in electronic configuration results in many similarities in the chemical behavior of carbon and silicon.

For example, both carbon and silicon can form a wide variety of compounds with other elements, including both organic and inorganic compounds. Both carbon and silicon can also exist in a variety of allotropes, which are different structural forms of the same element. Some of the allotropes of carbon include diamond, graphite, and fullerenes, while some of the allotropes of silicon include crystalline silicon, amorphous silicon, and silicon carbide.

There are also some differences between carbon and silicon. For example, carbon is a nonmetal, while silicon is a metalloid. Carbon has a lower melting point and boiling point than silicon. Carbon is also more electronegative than silicon.

Despite these differences, carbon and silicon are still more similar to each other than they are to any other element, and silicon is therefore the element that would be expected to behave the most like carbon.