1.) Mass
2.) Can occupy space (Volume)
Explanation:
Non-metals are the species that are electron deficient and they are able to accept one or more electrons from a donor atom in order to complete their octet.
For example, carbon (C), nitrogen (N), chlorine, (Cl), phosphorus (P) etc are all non-metals.
Metals are the species that contain more number of electrons in their valence shell and in order to attain stability they easily lose an electron.
For example, sodium (Na), lithium (Li), Beryllium (Be), Magnesium (Mg) etc are all metals.
Metalloids are the species that show properties of both metals and non-metals.
For example, Boron (B), Antimony (Sb), Silicon (Si) and Germanium (Ge) etc are metalloids.
1 elements
2 they have same number of valence electrons
3 period
The letter only has reflection symmetry, if you rotated it it would look the same.
