Mental confusion help: Hybridization. - Help.com

Electrons around an element have a statistical probability of where they will likely be around itself. We portray this probability in a cartoon of lobes which go around. The lobes are labeled s, p, d, f…and so on.

When you mix two atoms together the probability changes and you need new orbitals. Thus one s mixes with 3 p orbitals will be an sp3 orbital. Thus in your orbital diagram you would have four bonding orbitals.

In general, if you look at the shape of the molecule it will tell you the hybridization, tetrahedral is sp3, trigonal planar is sp2, linear is sp.

Mind you, it takes a whole text book to explain this so sorry if you don’t understand.

To answer your question PH3 is sp3. The orbital shape is trigonal pyramidal but it has a lone pair on top which gives it a general tetrahedral shape. This is just like ammonia.