Where can we found those in nature:
Metals can be found inside the electrical wiring, it was said that metals are great conductors of electricity and heat, and an example for this is copper. Non-metals can also be found outside the electrical wiring, they are the opposite of Non-metals on which they are insulators of electricity and heat, they are putted outside the copper or the metal so that the person that will handle or touch the wiring, he/she will not get electrocuted. Metalloids are combination of the properties of Metals and Non-Metals
Where can we found those in the periodic table:
Metals are found in the left side of the table, while it's opposite, Non-metals are found in the right side of the table, while the Metalloids are elements found diagonally between Metals and Non-Metals.
The group number indicates the number of valence electrons, this group number is found on every column.