The reason they were categorized different is they didn't have anything in common.
Well this is what i came with. They all are made up of electron, proton and neutrons.
all are non metals
Most non-metals do not have shiny appearances. They often have dull or non-reflective surfaces due to their lack of free electrons that can move around and reflect light. Some non-metals like iodine or graphite can appear shiny under certain conditions, but this is not common.
The most common metalloids are silicon, germanium, and arsenic. These elements exhibit properties of both metals and non-metals, making them important in various technological applications.
metals on left, non-metals on right, some others in middle.
Atoms of non-metals usually gain or share electrons when they react with other atoms.
they are all non metals
Non metals
alkai metals, alkaline earth metals, lanthanoids, actinoids, transistion metals, poor metals, other non-metals, noble gases.
Non-ferrous metals are metals that do not contain iron. Some common examples include aluminum, copper, lead, zinc, and brass. These metals are often used in industries such as electronics, aerospace, and construction due to their non-magnetic and corrosion-resistant properties.
Non metals
non metals
all are non metals
Most non-metals do not have shiny appearances. They often have dull or non-reflective surfaces due to their lack of free electrons that can move around and reflect light. Some non-metals like iodine or graphite can appear shiny under certain conditions, but this is not common.
My opinion would be metal. Since non metals are brittle and dull, I disagree with the non-metals.
They are in between the metals and non metals
The most reactive non metals are Halogens which may combine most of the metals as well as non metals.
They are all in the same group (column) of the Periodic Table and have the same number of valence electrons (4).