Since the chemical bonding between atoms involves the deformation of atomic electron wavefunctions, the radioactive half-life of an atom can depend on how it is bonded to other atoms. Simply by changing the neighboring atoms that are bonded to a radioactive isotope, we can change its half-life.

Half-life depends on probability because the atoms decay at a random time. Half-life is the expected time when half the number of atoms have decayed, on average. Carbon-14 has a half-life of 5,730 years. Taking one atom of carbon-14, this will either have decayed after 5,730 years, or it will not.

Half-lives can be calculated from measurements on the change in mass of a nuclide and the time it takes to occur. The only thing we know is that in the time of that substance’s half-life, half of the original nuclei will disintegrate.

Since half life is inversely proportional to K, then as K increases Half life decreases. So, half life decreases as temperature goes up.

Half life is increased by an increase in the volume of distribution and increased by a decrease in the rate of clearance. In some disease states (eg.

No temperature can affect rates of radioactive decays unless the temperature is high enough to cause the nuclei to strongly interact. That’s typically well over one million K. At ordinary temperatures electron clouds are interacting but nuclei are not.

You cannot stop it. If you change the stuff internally then you change the nucleus. You can do this by forceful reaction (transmutation) but then you have a new material or the same material in new nuclear state. Many physical properties may change with this change.

Many of the rocks in Earth’s crust and interior undergo this process of radioactive decay . This process produces subatomic particles that zip away, and later collide with surrounding material inside the Earth. Their energy of motion is converted to heat.

The radioactive decay of elements in the Earth’s mantle and crust results in production of daughter isotopes and release of geoneutrinos and heat energy, or radiogenic heat. Up to 90% of the Earth’s internal heat originates from radioactive decay.

The sun

And Earth is chock full of such radioactive elements—primarily uranium, thorium and potassium. Over the billions of years of Earth’s existence, the radioactive isotopes have been splitting, releasing energy as well as these antineutrinos—just like in a man-made nuclear reactor.

Earth moves very fast. It spins (rotates) at a speed of about 1,000 miles (1600 kilometers) per hour and orbits around the Sun at a speed of about 67,000 miles (107,000 kilometers) per hour. We do not feel any of this motion because these speeds are constant.

The crust

core

PROVIDENCE, R.I. — Scientists say they have discovered the thinnest portion of the Earth’s crust — a 1-mile thick, earthquake-prone spot under theAtlantic Ocean where the American and African continents connect.

The thermosphere

mesosphere

troposphere

the thermosphere

The majority of the mass of the entire atmosphere is contained in the troposphere—between approximately 75 and 80 percent. Most of the water vapor in the atmosphere, along with dust and ash particles, are found in the troposphere—explaining why most of Earth’s clouds are located in this layer.

Coldest layer of Earth’s atmosphere is the MESOSPHERE. The temperature there is -90 degree celsius. It can even go lower. Hottest layer of Earth’s atmosphere is the thermosphere.

The thermosphere is directly above the mesosphere and below the exosphere. The thermosphere is typically about 200° C (360° F) hotter in the daytime than at night, and roughly 500° C (900° F) hotter when the Sun is very active than at other times.

Fact Sheet

• The troposphere contains 75% of the atmosphere’s total mass.
• In either space or time the troposphere is not constant.
• Weather occurs in the troposphere.
• The troposphere is 10 miles from the equator.
• The troposphere is 5-7 miles above the poles.
• Does not contain ozone.

The thermosphere is the fourth layer, and it absorbs the sun’s radiation, making it very hot. The thermosphere puts on a dazzling light show (the auroras) cause by colliding particles, and the thermosphere is also where satellites orbit the Earth. The thermosphere is one busy layer!

The thermosphere lies between the exosphere and the mesosphere. “Thermo” means heat, and the temperature in this layer can reach up to 4,500 degrees Fahrenheit. If you were to hang out in the thermosphere, though, you would be very cold because there aren’t enough gas molecules to transfer the heat to you.

The thermo- in thermosphere means “heat.” Even though the air in the thermosphere is thin, it is very hot, up to 1,800°C. This is because sunlight strikes the thermosphere first. Nitrogen and oxygen molecules convert this energy into heat.

Though the thermosphere has high temperature, it does not feel hot. Temperature is a measure of the energy of particles. Heat is generated when particles touch one another. Particles in the thermosphere are so far apart they don’t transfer much energy to one another.

thermosphere—temperature increases with height. The temperatures can rise to 1,500 degrees Celsius, but it would not feel warm because of the low air pressure in this layer. mesopause—the boundary between the mesosphere and the thermosphere; the coldest place on Earth.