12
2 The Kinds of Ordinary Materials
has molecules with two deuterium atoms bound to one oxygen atom. 2 Binding two
neutrons with one proton makes tritium (T), but this nucleus is not stable, decaying
to helium-3 ( 3
2 He), an electron, and an antineutrino, with a half-life of 12.3 years.
Almost all the heavier elements beyond hydrogen, deuterium, lithium, helium and
beryllium came from the supernovae debris of the explosions of dying individual
stars and the explosions resulting from dense-star merges. Elements up to iron in
atomic weight result from cooking in stars over millions of years before exploding,
while those heavier than iron are made in the seconds after the explosion.
The planets of the solar system arose from stellar debris: rocks, dust, and gases,
released from early supernovae and stellar merges. Within the gas, dust, and rocks
were the chemicals needed for life. Because of thermal gradients, the chemicals
were naturally differentiated in regions around the Sun, in the molten interiors of
planets, and in the liquids which formed on the surface of planets after cooling.
Today, the predominant gases in the Earth’s atmosphere at sea level are nitrogen
(78%), oxygen (21%), water vapor (∼1%), argon (0.93%), carbon dioxide (0.04%),
and trace amounts of neon, helium, krypton, methane, hydrogen, radon and volatile
organics. 3 Elements in the Earth’s crust, found mostly as compounds, include
oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, titanium,
hydrogen, phosphorus, manganese, fluorine, barium, carbon, strontium, and sulfur,
these given in order of abundance.
To understand the differentiation of elements and compounds on Earth, and
the various phases possible for the resulting material, we need to understand the
forces between atoms and the natural processes of differentiation at prevailing
temperatures and differences of temperatures across the space occupied by the
materials.
Atoms have a positively-charged nucleus (made from protons and neutrons)
surrounded by negatively-charged electrons, with a total charge of zero. The
electrons most distant from the nucleus take part in chemical bonding of atoms, and
are called ‘valence electrons’. These electrons near the ‘surface’ of the atom are held
with the least average force, and require typically about 0.1 to 10 electron volts of
energy to release one of them. 4 If an electron is shared between two or more atoms,
causing the atoms to hold together over distances in the tenths of a nanometer, the
resulting chemical bond is called ‘covalent’. If the sharing is unequal, with the center
of charge for the shared electron not centered halfway between the atoms, then the
2 Curiously, if you drink a bottle of pure heavy water, you are likely to die. This observation came
via a private communication in 1975 from Prof. Robert Corbin Vincent, Chemistry Dept., GWU,
while he held up a pint of liquid deuterium oxide, and explained that the lethality comes from the
fact that the D + ion moves about 30% slower than its cousin p + , hindering critical biochemical
reaction rates.
3 When the Earth was formed about 4.54 ± 0.05 billion years ago, the Earth’s atmosphere had little
oxygen. Our present atmospheric oxygen was produced by the activity of cyanobacteria and then
plants, starting about 2.5 ± 0.2 billion years ago.
4 In comparison, the average kinetic energy of a small atom or molecule in your body is about
0.04 eV, due to its thermal motion.
2 The Kinds of Ordinary Materials
has molecules with two deuterium atoms bound to one oxygen atom. 2 Binding two
neutrons with one proton makes tritium (T), but this nucleus is not stable, decaying
to helium-3 ( 3
2 He), an electron, and an antineutrino, with a half-life of 12.3 years.
Almost all the heavier elements beyond hydrogen, deuterium, lithium, helium and
beryllium came from the supernovae debris of the explosions of dying individual
stars and the explosions resulting from dense-star merges. Elements up to iron in
atomic weight result from cooking in stars over millions of years before exploding,
while those heavier than iron are made in the seconds after the explosion.
The planets of the solar system arose from stellar debris: rocks, dust, and gases,
released from early supernovae and stellar merges. Within the gas, dust, and rocks
were the chemicals needed for life. Because of thermal gradients, the chemicals
were naturally differentiated in regions around the Sun, in the molten interiors of
planets, and in the liquids which formed on the surface of planets after cooling.
Today, the predominant gases in the Earth’s atmosphere at sea level are nitrogen
(78%), oxygen (21%), water vapor (∼1%), argon (0.93%), carbon dioxide (0.04%),
and trace amounts of neon, helium, krypton, methane, hydrogen, radon and volatile
organics. 3 Elements in the Earth’s crust, found mostly as compounds, include
oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, titanium,
hydrogen, phosphorus, manganese, fluorine, barium, carbon, strontium, and sulfur,
these given in order of abundance.
To understand the differentiation of elements and compounds on Earth, and
the various phases possible for the resulting material, we need to understand the
forces between atoms and the natural processes of differentiation at prevailing
temperatures and differences of temperatures across the space occupied by the
materials.
Atoms have a positively-charged nucleus (made from protons and neutrons)
surrounded by negatively-charged electrons, with a total charge of zero. The
electrons most distant from the nucleus take part in chemical bonding of atoms, and
are called ‘valence electrons’. These electrons near the ‘surface’ of the atom are held
with the least average force, and require typically about 0.1 to 10 electron volts of
energy to release one of them. 4 If an electron is shared between two or more atoms,
causing the atoms to hold together over distances in the tenths of a nanometer, the
resulting chemical bond is called ‘covalent’. If the sharing is unequal, with the center
of charge for the shared electron not centered halfway between the atoms, then the
2 Curiously, if you drink a bottle of pure heavy water, you are likely to die. This observation came
via a private communication in 1975 from Prof. Robert Corbin Vincent, Chemistry Dept., GWU,
while he held up a pint of liquid deuterium oxide, and explained that the lethality comes from the
fact that the D + ion moves about 30% slower than its cousin p + , hindering critical biochemical
reaction rates.
3 When the Earth was formed about 4.54 ± 0.05 billion years ago, the Earth’s atmosphere had little
oxygen. Our present atmospheric oxygen was produced by the activity of cyanobacteria and then
plants, starting about 2.5 ± 0.2 billion years ago.
4 In comparison, the average kinetic energy of a small atom or molecule in your body is about
0.04 eV, due to its thermal motion.