What are groups 1, 2, and 3 on the periodic

Group 1 = Alkali metals
Group 2 = Alkaline earth metals
Group 3 = Lathanoids

Number of Atoms in Methanol are calculated as,

Write chemical formula of Methanol,

                                                      CH₃-OH

Find out Subscripts:
                                There is only one subscript (₃) written after Hydrogen, it means there are 3 Hydrogen atoms attached to Carbon atoms.

Add all atoms in molecule:
                                           Carbons  =   1
                                       Hydrogens  =   4
                                          Oxygens  =   1
                  Total Atoms                       
                          
                                                               6 Atoms