(Note that the electron is assigned an “atomic number” of –1, equal to its charge.) The third major type of radioactive emission is not a particle but rather a very energetic form of electromagnetic radiation called , symbolized by the Greek letter γ.Gamma rays themselves do not carry an overall electrical charge, but they may knock electrons out of atoms in a sample of matter and make it electrically charged (for which gamma rays are termed Write the nuclear equation that represents the radioactive decay of boron-12 by beta particle emission and identify the daughter isotope.(This constant drain on the battery explains why the batteries in smoke detectors should be replaced regularly, whether the alarm has been triggered or not.) When particles of smoke from a fire enter the smoke detector, they interfere with the ions between the metal plates, interrupting the flow of current.
If our uranium nucleus loses 2 protons, there are 90 protons remaining, identifying the element as thorium.
Moreover, if we lose four nuclear particles of the original 235, there are 231 remaining.
The two isotopes of hydrogen—H—are given their own names and symbols: deuterium (D) and tritium (T), respectively.
Atomic theory in the nineteenth century presumed that nuclei had fixed compositions.
Applications of nuclear chemistry may be more widespread than you realize.
Many people are aware of nuclear power plants and nuclear bombs, but nuclear chemistry also has applications ranging from smoke detectors to medicine, from the sterilization of food to the analysis of ancient artifacts.
Next to the plates is a small disk containing a tiny amount (∼0.0002 g) of the radioactive element americium.
The radioactivity of americium ionizes the air between the plates, causing a tiny current to constantly flow between them.
Most chemists pay little attention to the nucleus of an atom except to consider the number of protons it contains because that determines an element’s identity.
However, in nuclear chemistry, the composition of the nucleus and the changes that occur there are very important.
The overall mass number stays the same, but because the number of protons increases by one, the atomic number goes up by one.