In the three-dimensional structure of methane, ch4, the hydrogen atoms attached to a carbon atom are aligned in the three-dimensional structure of methane, ch4, the hydrogen atoms attached to a carbon atom are aligned at the corners of a square at the corners of a tetrahedron at the corners of a cube in a straight line at the corners of a rectangle

            In the three-dimensional structure of methane, CH₄, the hydrogen atoms attached to a carbon atom are aligned at the corners of a Tetrahedron.

Explanation:
                   In Methane (CH₄) the central atom (carbon) is bonded to four hydrogen atoms. So, the central atom is having four electron pairs and all pairs are bonding pairs and lacks any lone pair of electron. According to Valence Shell Electron Pair Repulsion (VSEPR) Theory the central atom with four bonding pair electrons and zero lone pair electrons will attain a tetrahedral geometry with bond angles of 109°. Hence, the shape of CH₄ is tetrahedral.

Yes it would be a physical change.