What Goes On Inside The Atom-Radioactivity
Many atoms are radioactive, which means their nuclei are unstable.
Radioactive atoms emit particles or energy to lower the energy of the nucleus and regain stability.
One reason for instability is that the atom is just too plain big.
If the number of protons and neutrons combined exceed sixty, then two smaller particles with the same combined number of protons and neutrons will have lower energy than the big atom.
Atoms can therefore lower energy by splitting into two smaller particles.
The most common way for an atom to do this is by ejecting an alpha particle (this is called alpha decay).
An alpha particle has two protons and two neutrons and is exceptionally stable.
Alpha decay is sometimes taken as evidence that protons and neutrons cluster together in alpha particles inside the neutrons.
Alpha particles are the most damaging of all radiation to humans, but they have the least penetrating ability.
In rarer cases, an atom can release even bigger particles, or split up into two particles of the same size.
Of course, humans have taken advantage of this process to release energy by artificially splitting an atom into two smaller ones, a process called nuclear fission.
The converse of nuclear fission is that for very small atoms, one can release energy by putting them together, a process called nuclear fusion.
This goes on all the time in the Sun, but as of yet we haven't managed to recreate these conditions ourselves in order to do anything useful (unless you count H-bombs as useful).
Another reason for instability inside an atom is that there is an imbalance of protons and neutrons inside the nucleus.
Rectifying this requires that a neutron decay into a proton or a proton is converted to a neutron.
The most common case is that of too many neutrons; a neutron decays into a proton by emitting an electron and a much smaller particle called a neutrino.
If there are too many protons, what can happen is that a proton 'captures' one of the electrons orbiting around the nucleus and interacts with it to form a neutron.
This process can also be accompanied by another process where a proton converts to a neutron by emitting a positron (exactly like an electron, but with positive charge) and a neutrino.
All these processes fall under the generic title of beta decay.
A nucleus could also be unstable because the protons and neutrons inside are occupying high energy levels.
After a rearrangement of the internal structure, the excess energy is emitted.
In the case of electrons, we saw this energy was emitted in the form of light photons.
Here, the photons have much more energy and are called gamma radiation.
This kind of decay, known as gamma decay, often happens after alpha decay or nuclear fission, as the two particles readjust their structure after splitting.
Radioactive atoms emit particles or energy to lower the energy of the nucleus and regain stability.
One reason for instability is that the atom is just too plain big.
If the number of protons and neutrons combined exceed sixty, then two smaller particles with the same combined number of protons and neutrons will have lower energy than the big atom.
Atoms can therefore lower energy by splitting into two smaller particles.
The most common way for an atom to do this is by ejecting an alpha particle (this is called alpha decay).
An alpha particle has two protons and two neutrons and is exceptionally stable.
Alpha decay is sometimes taken as evidence that protons and neutrons cluster together in alpha particles inside the neutrons.
Alpha particles are the most damaging of all radiation to humans, but they have the least penetrating ability.
In rarer cases, an atom can release even bigger particles, or split up into two particles of the same size.
Of course, humans have taken advantage of this process to release energy by artificially splitting an atom into two smaller ones, a process called nuclear fission.
The converse of nuclear fission is that for very small atoms, one can release energy by putting them together, a process called nuclear fusion.
This goes on all the time in the Sun, but as of yet we haven't managed to recreate these conditions ourselves in order to do anything useful (unless you count H-bombs as useful).
Another reason for instability inside an atom is that there is an imbalance of protons and neutrons inside the nucleus.
Rectifying this requires that a neutron decay into a proton or a proton is converted to a neutron.
The most common case is that of too many neutrons; a neutron decays into a proton by emitting an electron and a much smaller particle called a neutrino.
If there are too many protons, what can happen is that a proton 'captures' one of the electrons orbiting around the nucleus and interacts with it to form a neutron.
This process can also be accompanied by another process where a proton converts to a neutron by emitting a positron (exactly like an electron, but with positive charge) and a neutrino.
All these processes fall under the generic title of beta decay.
A nucleus could also be unstable because the protons and neutrons inside are occupying high energy levels.
After a rearrangement of the internal structure, the excess energy is emitted.
In the case of electrons, we saw this energy was emitted in the form of light photons.
Here, the photons have much more energy and are called gamma radiation.
This kind of decay, known as gamma decay, often happens after alpha decay or nuclear fission, as the two particles readjust their structure after splitting.