Final answer:
In a Lewis diagram for methane (CH4), the central atom is carbon. It forms four bonds with hydrogen atoms, and these are arranged in a tetrahedral geometry with bond angles of 109.5° due to sp³ hybridization of the carbon atom.
Step-by-step explanation:
In the Lewis diagram for methane (CH4), the central atom is carbon. Carbon contributes four valence electrons, which are shared with one valence electron from each of the four hydrogen atoms, resulting in four C-H bonds. These bonds are arranged in a tetrahedral geometry to minimize electron repulsion, with the carbon atom at the center and the hydrogen atoms at the corners of the tetrahedron. The molecular geometry of methane is therefore described as tetrahedral, with bond angles of approximately 109.5°. In CH4, the carbon atom undergoes sp³ hybridization, which means that its four valence electrons are equally distributed among the hybrid orbitals before pairing with electrons from hydrogen atoms during bond formation.