Term
| What is Dalton's atomic theory? |
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Definition
| States that matter is composed of extremely small particles called atoms; atoms are invisible and indestructable; atoms of a given element are identical in size, mass, and chemical properties; atoms of a specificelement are different from those of another element; different atoms combine in simple whole-number ratios to form compounds; in a chemical reation, atoms are separated, combined, or rearranged |
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Term
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Definition
| the smallest particle of an element that retains all the properties of that element; is electrically neutral, spherically shaped, and composed of electrons, protons, and neutrons |
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Term
| What is the atomic mass unit (amu)? |
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Definition
| one-twelfth the mass of a carbon-12 atom |
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Term
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Definition
| the weighted average mass of the isotopes of the element-the mass of the protons and neutrons in an element |
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Definition
| the number of protons in an atom |
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Term
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Definition
| atoms of the same elemnt with differnt numbers of neutrons |
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Term
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Definition
| the number after an element's name that represents the sum of the protons and neutrons |
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Term
| What is an alpha particle? |
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Definition
| a particle with two protons and two neutrons, with a 2+ charge; is equivalent to a helium-4 nucleus, is emitted during radioactive decay |
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Term
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Definition
| radiation that is made up of alpha particles; is deflected toward a negatively charged plate when radiation from a radioactive source is directed between two electrically charged plates |
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Term
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Definition
| a high-speed electron with a 1- charge that is emitted during radioactive decay |
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Definition
| radiation that is made up of beta particles; is deflected toward a postively charged plate when ratiation from a radioactive source is directed between two electrically charged plates |
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Term
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Definition
| high energy radiation that has no electrical charge and no mass, is not deflected by electric or magnetic fields, usually accompanies alpha and beta radiation and accounts for most of t he energy lost during radioactive decay |
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Term
| What is a nuclear equation? |
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Definition
| a type of equation that shows the atomic number and mass number of the particles involved |
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Term
| What is a nuclear reaction? |
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Definition
| a reaction that involves a change in the nucleus of an atom |
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Term
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Definition
| the rays and particles-alpha and beta particles and gamma rays-that are emitted by radioactive materials |
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Term
| What is radioactive decay? |
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Definition
| a spontaneous process in which unstable nuclei lose energy by emitting radiation |
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Term
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Definition
| the process in which some substances spontaneously emit radiation |
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Term
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Definition
| the positive region in a cathode ray |
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Term
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Definition
| the negative region in a cathode ray |
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Term
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Definition
| radiation that originates from the cathode and travels to the anode of a cathode-ray tube |
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Term
| What were Democritus' views on matter and the atom? |
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Definition
| matter is composed of atoms that move through empty space; atoms are solid, homogeneous, indestructible, and indivisible; different kinds of atoms have different sizes and shapes; size, shape, and movement of atoms determine the properties of matter |
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Term
| What were Aristotle's ideas about matter? |
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Definition
| empty space cannot exist and matter is made of earth, fire, air, and water |
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Term
| What was J.J. Thomson's model? |
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Definition
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Term
| What was Rutherford's experiment/model? |
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Definition
| the one where he shot an alpha particle through the sheet of gold. some bounced back and others went through. this showed that atoms had dense nuclei; Rutherford also said that the atom had protons |
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Term
| What was Chadwick's discovery? |
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Definition
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Term
| What is the mass of a proton? |
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Definition
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Term
| What is the mass of a neutron? |
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Definition
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Term
| What is the mass of an electron? |
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Definition
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Term
| How are atomic mass and mass number the same? different? |
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Definition
| Atomic mass and mass number have the same numerical value, but atomic mass has a unit |
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Term
| When adding an alpha particle, what do you do? |
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Definition
| subtract 4 from the mass number and 2 from the atomic number |
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Term
| When adding a beta particle, what do you do? |
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Definition
| add one to the atomic number, but the mass number remains the same |
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Term
| Where is a beta particle from? |
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Definition
| the desintigration of a neutron |
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Term
| Why does a gamma ray have no mass? |
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Definition
| because it isnt a particle |
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