Biophysics of Ionizing Radiation - Radioelements

Flashcards testing fundamental concepts of radioelements, atomic structure, nuclear characteristics, and historical discoveries in biophysics.

The property of certain chemical elements to emit radiation spontaneously due to nuclear instability is known as __________.

radioactivity

X-rays were discovered in 1895 by __________.

Wilhelm Conrad Roentgen

Natural radioactivity was discovered in 1896 by __________ through the observation of radiation emitted by uranium salts.

Henri Becquerel

In 1898, Pierre and Marie Curie discovered the radioactive elements polonium and __________ in uranium ore.

radium

Artificial radioactivity was discovered in 1934 by Irène and __________ Joliot-Curie.

Frédéric

In the atomic model developed by Bohr in 1913, electron shells are designated by letters, with the innermost shell ($n = 1$) designated as __________.

K

The maximum number of electrons that can occupy a quantum level of rank $n$ is given by the formula __________.

$$2 n^2$$

When the energy supplied to an atom is sufficient to strip an electron from its orbit, the atom becomes a positively charged ion in a phenomenon called __________.

ionisation

The mass of a proton is approximately $1.673 \times 10^{-27}\text{ kg}$, which is about __________ times the mass of an electron.

1836

The total number of nucleons in an atomic nucleus is represented by the mass number __________.

$$A$$

Because an atom is electrically neutral, the atomic number $Z$ equals both the number of protons and the number of __________.

electrons

The standard representation of a neutron as an elementary particle is __________.

$$_0^1 n$$

One atomic mass unit ($\text{u.m.a.}$) is defined as $\frac{1}{12}\text{th}$ of the mass of an atom of __________.

$$^{12}\text{C}$$

In energy units, one atomic mass unit ($\text{u.m.a.}$) is equivalent to approximately __________.

$$931\text{ MeV/c}^2$$

The difference between the sum of the individual nucleon masses and the actual mass of the nucleus is called the __________.

mass defect

The energy needed to separate a nucleus completely into its individual constituent nucleons is called the __________.

binding energy

Nuclides that have the same atomic number $Z$ but different mass numbers $A$ are called __________.

isotopes

The three natural isotopes of hydrogen shown in the diagram are Hydrogen ($^1_1\text{H}$), Deuterium ($^2_1\text{H}$), and __________ ($^3_1\text{H}$).

Tritium

Nuclides with the same mass number $A$ but different atomic numbers $Z$ are known as __________.

isobars

Nuclides with the same neutron number $N$ but different atomic numbers $Z$ and mass numbers $A$ are known as __________.

isotones

Metastable states ($^m_A X$) of a nucleus are unstable states that have a lifetime greater than __________.

$$10^{-12}\text{ s}$$

Technetium-99m ($^{99m}_{43}\text{Tc}$) transitions to its ground state isomer Technetium-99 ($^{99}_{43}\text{Tc}$) via an isomeric transition accompanied by the emission of a __________.

photon