Atoms : The Proton
The proton is the second largest particle of the atom.
Protons are positioned outside the nucleus of every
atom. Every atom contains a specific number of protons.
Discovery
The proton was discovered when, in 1919, Lord Ernest Rutherford, an english
chemist, discovered the nucleus of an atom. During the 1960's and 1970'
scientist discovered that the particles of the nucleus were made up of
smaller particles called quarks. Up quarks have a slightly positive
charge and down quarks have a slightly negative charge. The proton is made
up of 3 smaller particles called quarks. 
Each
proton has 2 up and one down quark.
Size
Protons are about nm in diameter. A nanometer (nm) is 1/10000 of a meter.
Mass of proton : 1,6726 x 10^(-27) kg
Proton Position
The proton is located in the center of the atom or the
nucleus. Protons only leave the nucleus during nuclear
fission.
Proton Number
The number of protons in an atom determines the element
of that atom. Scientists call the number of protons the atomic number of
an element.
For example, the atomic
number of the element Helium is 2, therefore Helium atoms have 2 protons
in the nucleus.
If the atomic number of an atom is known, scientist
can then look at a chart known as the Perdic Table of Elements to locate
the name of the element.
page created by Paula Jarrett Nasta
last updated 4/27/02