Yes, in an alkane, all carbon atoms are surrounded by individual groups and are therefore hybridized with a tetrahedral geometry. This means that the four bonds around each carbon atom are arranged in a three-dimensional tetrahedron, with bond angles of 109.5 degrees.
To understand why this is the case, we need to consider the electronic configuration of carbon. In its ground state, carbon has two unpaired electrons in its valence shell. These electrons can be used to form two covalent bonds. However, in order to form four covalent bonds, carbon must undergo hybridization.
During hybridization, one 2s electron and three 2p electrons are combined to form four new hybrid orbitals. These hybrid orbitals are called sp3 orbitals because they have a 25% s character and 75% p character. The sp3 orbitals are arranged in a tetrahedral geometry, which allows the carbon atom to form four covalent bonds with other atoms.
All carbon atoms in alkanes are sp3 hybridized. This means that they are all tetrahedral in shape and have bond angles of 109.5 degrees. This is why alkanes are typically very stable and non-reactive molecules.
Here is a diagram of a methane molecule, which is the simplest alkane:
The carbon atom in methane is sp3 hybridized, and the four hydrogen atoms are arranged in a tetrahedron around it. This gives the methane molecule its characteristic tetrahedral shape.
I hope this helps!