Unlike rocks, all and

a) are expensive, are difficult to get.

b) occur naturally, have a fixed chemical composition.

c) contain metal, dissolve in acid.

d) fracture, contain silica

Which statement best describes the he properties of iconic compounds ?

Phosphorous can form an ion called phosphide, which has the formula p3−. this ion can form an ion called phosphide, which has the formula p3−. this ion properties very similar to those of pforms when a phosphorus atom loses three protonsis called a cationcontains 18 electrons

Who discovered a pattern to the elements in 1869?