Term
| What is the most abundant atom in the body? |
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Definition
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| Which part of the atom is both the smallest in volume but containts all of it's mass? |
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| The mass of the nucleus is mostly made up of what particles? |
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Definition
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| What are the two types of nucleons? |
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| What is the atomic number of an atom? |
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Definition
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| What is the mass number of an atom? |
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| Which number gives an atom its chemical identity? |
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Definition
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Definition
| Atoms of elements with the same number of protons (atomic) but different number of neutrons (mass). |
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Term
| What is Heisenberg's Uncertainty Principle? |
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Definition
| Position of an electron in the cloud is not predictable because it depends on the electron's energy at any moment in time. |
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Term
| When i an atom electrically stable? |
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Definition
| When it has same number of protons and electrons. |
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Term
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Definition
| An atom that is electrically unstable. |
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Term
| What are the three types of motion within an atom? |
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Definition
Electrons spinning on their own axes.
Electrons orbiting the nucleus.
Nucleus spinning on its own axis. |
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Term
| Why does a nucleus with an even mass number have no net spin? |
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Definition
| Because the protons and neutrons spin in pairs, in opposite directions at the same speed - so they balance each other out. |
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Term
| A nucleus with an odd mass number has a net spin, aka _____ _______. |
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Definition
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Term
| Nuclei with angular momentum (or net spin due to imbalance of protons and neutrons) are known as ___ _____ nuclei. |
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Definition
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Term
| MR active nuclei are characterized by their tendency to align their axis of rotation to what? |
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Definition
| An applied magnetic field. |
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Term
| Faraday's law of electricomagnetic induction refers to what 3 individual forces? |
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Definition
| Motion, magnetism, and charge. |
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Term
| What does Faraday's law say about motion, magnetism, and charge? |
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Definition
| If any two are present, the third is automatically induced. |
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Term
| MR active nuclei which have a net charge and are spinning automatically acquire a ______ ______ |
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Definition
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Term
| MR active nuclei with a magnetic moment can align with an ______ ______ _____ |
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Definition
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Term
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Definition
| Low energy nuclei which align themselves in the same direction as Bo. |
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Term
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Definition
| The name given to the main magnetic field. Also known as the static external magnetic field. This is the field created by the MRI machine. |
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Term
| anti-parallel or spin-down |
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Definition
| Higher energy nuclei which align themselves in the opposite direction as Bo. |
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Term
| net magnetization vector (NMV) |
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Definition
| This reflects the relative balance between spin-up and spin-down nuclei. |
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Definition
| The main unit of meausurement of magnetic strength. |
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Term
| 1 Tesla (T) = _______ gauss (G) |
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Definition
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Definition
| The additional spin or wobble of magnetic moments of hydrogen around Bo (additional to the spinning on its own axis) |
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Definition
| the circular path the magnetic moment follows around Bo. |
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Definition
| speed at which hydrogen's magnetic moments wobble around Bo. |
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Definition
| precessional frequency = Bo x gyromagnetic ratio. |
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Definition
| precessional frequency of hydrogen at 1 T |
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Definition
| precessional freq.of hydrogen at 1.5 T |
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Term
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Definition
| precessional freq. of hydrogen at 0.5 T |
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