They range in size from about 100nm down to about 1nm.
usally thr size of small molecules, to small to see with a microscope.
They have a large surface area compared with their volume. This enables them to react very quickly which makes them useful as catalysts to speed up reactions.
They have different properties to the same substance in normal-sized pieces.
titanium dioxide is a white solid used in house paint and certain sweet coated chocolates. Titanium dioxide nanoparticles are so small they do not reflect visible light, so cannot be seen.
They are used in suncream to block ultraviolet light without appering white on the skin.
May lead to;
Stronger and Lighter Building Materials