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Radiation Biology
Exam 1
Question | Answer |
---|---|
What is matter? | Anything that takes up space and has form or shape |
What are atoms? | Fundamental building blocks of all matter, i.e. hydrogen atom. |
What is mass? | The quantity of matter contained in any physical object. more matter = more mass |
What is weight? | The force exerted on an object under the influence of gravity. |
What is energy? | The ability to do work, measured in joules (SI units) or eV. Examples are kinetic energy, electromagnet energy and chemical energy. |
Define radiation. | The transfer of energy or energy in transit from one location to another. |
What are the two main parts of an atom? | Nucleus and electron cloud |
What are the parts of the nucleus? | Neutrons and protons |
Describe a Bohr atom. | Electrical in nature. Nucleus: proton has a positive charge and neutron has 0 charge. Electrons move in orbits with a shell and specific energy levels-they spin on their axis. Electrons are negatively charged. |
Specify the number of electrons per shell. | K:2, L:8, M:18, N:32 |
Which shell is most binding/least binding and why? | K shell as it is closest to the nucleus, the last shell as it is furthest away |
Electron shell properties.... | Electrons near nucleus are more tightly bound. Outer shells more loosely bound. Valence is the outer most shell |
What is force? | That which changes the motion of an object, a push or a pull (measured in Newtons) |
Centrifugal force... | forse that causes an electron to travel staight and try to leave the atom |
Centripetal force.... | the center seeking force:opposite charges attract |
Conditions needed for x-ray production | -source (high voltage electric current)-acceleration of electrons-concentration of electrons-deceleration of electrons |
Ionization | the removal of an orbital electron from an atom. Occurs exclusively through the addition or removal of orbital electrons and forms an ion pair |
Atomic Nomenclature, what does the X stand for...the Z (subscript).....the A (superscript) | X = the elementZ = the number of protons (the atomic number)A = the atomic mass (# of protons and neutrons) |
What are isotopes | atoms that have the same atomic number (same element) but different mass numbers (has more or fewer neutrons) Ex. radioisotopes used in Nuclear Medicine |
What are isobars? | atoms that have the same atomic mass but different atomic numbers (are different elements) ex. I-131 and Xe-131 |
What are isotones? | Atoms that have the same number of neutrons but different numbers of protons. Ex. Xe-131 and Cs-132 these have the same number of neutrons |
What is an element | a substance made up of atoms that all have the same atomic number therefore the same chemical properties |
What is an isomer | Atoms that have the same atomic number and the same atomic mass number. They are idential except that they exist at different energy states. Ex. technetium 99m (m stands for metastable meaning more lasting) and Technitium 99 |
What makes an atom stable | Having equal number of protons and neutrons |
What are unstable atoms | Radioactive....they emit alpha particles, beta particles and/or gamma rays |
Radioactivity | defines as the process by which an unstable atom attempts to reach stability. The nucleus spontaneously emits particles and energy thereby transforming itself into another atom in order to become more stable |
Define Radiation | energy in transit from one location to anotherthe energy emitted and transferred through matter |
What is the electromagnetic spectrum | spectrum includes the entire range of electromagnetic radiation including ionizing and non ionizing forms.A chart demonstrating the values of energy, frequency and wavelength. |
What are the only type of ionizing electromagnetic radiation | X ray and Gamma rays |
What are non ionizing radiation | MRI and radiowaves |
Define ionization | the removal of an electron from an atom |
Where are X ray and Gamma Rays on the spectrum | They are at the highest end of the spectrum therefore they have the highest energy, highest frequency and shortest wavelength. |
Where do x rays originate | in the electron cloud |
where do gamma rays originate | in the nucleus |
What is the main difference between xray and gamma rays | where they originate |