Studied by 0 people1nm =
10-9 m
Size of nanoparticles
1-100nm in size
Bulk material
Not a nanoparticle
The smaller a particle
the larger the surface area to volume ratio
As a cube decreases in size by a factor of 10
Its surface area:volume ratio increases by a factor of 10
Nanoparticles have different properties to bulk materials because
Most atoms are at the surface and they have a high surface area to volume ratio
Uses of nanoparticles
Catalysts, in electronics, in sunscreens.
Advantages of nanoparticles in sunscreen
Better coverage, more effective protection from UV
Disadvantages of nanoparticles in sunscreen
Small enough to enter the bloodstream, could damage cells, could damage the environment
Number of atoms in a nanoparticle
A few hundred atoms
Risks of nanoparticles are unknown
They have not been used for very long
Properties of nanoparticles
Very different to bulk material
Ion
atom or group of atoms that has a positive or negative charge
Polyatomic ion
An ion made of two or more atoms
Ionic compound
A compound that consists of positive and negative ions
Formation of ionic compounds
Metal gives electron(s) to non-metals
Ionic formula
The simplest whole number ratio of the ions which form a neutral ionic compound
Charges in an Ionic Compound
Cancel one another out
Hydroxide ion
OH-
Carbonate ion
CO3 2-
Nitrate ion
NO3-
Ammonium ion
NH4+
(s)
Solid
(l)
Liquid
(g)
Gas
(aq)
Aqueous
Note 
Flashcard (216)