A metal is generally considered to be a pure element which readily forms cations. Metals are characterised by their opacity and high thermal and electrical conductivities, the latter properties resulting from the delocalised and mobile nature of the electrons over the crystal structure.
A liquid or paste used for writing, printing or drawing. In many instances it is a colloidal sol system of fine pigment particles dispersed in a solvent. The ink will impart colour and its properties by being adsorbed/absorbed onto the substrate, often via ionic bonding.