Atoms of many elements readily lose and others gain electrons to become positively and negatively charged ions respectively. In turn, positive and negative ions attract together to form minerals, ionic bonding (see text). Depending on their charge and size ions will pack together in specific ways to give mineral crystals of distinctive color and shape. For examples, type into your browser: mineral crystals images/ For the chemical composition of a mineral, type into your browser: chemical composition of ________ (name of mineral)/
Difference between a rock and mineral: A rock is comprised of two or more minerals intermixed.
Problem: Show students any rock or mineral and ask: How are atoms bonded together in this ___? It is bound to be ionic bonding.
Table salt is a mineral, sodium chloride (NaCL), positive sodium ions packed together with negative chloride ions. The size of these ions is such that they pack together to make a cube as shown in various diagrams.
Type into your browser: molecular structure of table salt/
Examine salt grains with a pocket magnifier. You will see the each grain is a tiny cube.