- published: 08 Jan 2012
- views: 399259
Isotopes are variants of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos (ἴσος "equal") and topos (τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table. The number of protons within the atom's nucleus is called atomic number and is equal to the number of electrons in the neutral (non-ionized) atom. Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.
For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons, so that the neutron numbers of these isotopes are 6, 7 and 8 respectively.
Dead of the winter
snow gently falling
stillness surrounds us
church bells are calling
Out in the distance
Cuts thru the grey clouds
I couldn't live here now
But maybe someday
Maybe one day soon
Dead of the winter
Tracks in the new snow
See where they lead to
See where they will go
Into the forest
somebodys waiting
I wouldn't go there now
You do what you want
You do or you don't
Your call
Carbon emissions
de-forestation
Antarctic warming
Land degradation
Fuel-wood consumption
Urbanization
I couldn't live here now