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Chapter 4
Chem Chapter 4
| Question | Answer |
|---|---|
| Discovered radioactivity, which occurred when he found that the element uranium (in a sample of pitchblende) emitted invisible rays that could darken a photographic plate | Henri Becqueral |
| Found that atoms consist mostly of empty space and have a small nucleus | Lord Rutherford |
| Found that rays are given off by uranium and radium | Marie Curie |
| Discovered transuranium elements and patented berkelium and californium | Seaborg |
| Discovered x-rays | Roentgen |
| A change in which one or more substances are changed into one or more new substances | Chemical reactions |
| A reastion, as in fission, fusion, or radioactive decay, that alters the energy, composition, or structure of an atomic nucleus | Nuclear reactions |
| Particles that make up the atomic nucleus | Nucleon |
| Particular kind of atom containing a definite number of protons and neutrons | Nuclide |
| The changing of one element into another | Transmutation |
| A reaction that changes the number of protons in the nucleus, an atom w/ a new atomic # is obtained | Induced transmutation |
| Members of the actinide series | Transuranium elements |
| Breaking apart of an unstable nucleus into two roughly equal parts | Fission |
| When two or more small nuclei melt together to form one larger nucleus | Fusion |
| Do nuclear reactors use fission or fusion to generate energy? | Fission, because an atom needs to be split in order to generate energy |
| The length of time it takes for one-half of the atoms to disintegrate | Half-life |
| What most likely makes a nucleus more stable and less likely to decay? | Even number of protons and neutrons and not too'big' |
| Compare and contrast alpha particles, beta particles, and gamma radiation in terms of composition, energy, mass, and penetrating ability | Alpha particles - helium nucleus consisting of 2 protons and 2 neutrons, low energy, roughly 4.0015 amu, low penetrating ability Beta particles - high-speed electron, high energy, light mass, greater penetrating ability |
| Compare and contrast alpha particles, beta particles, and gamma radiation in terms of composition, energy, mass, and penetrating ability (cont'd) | Gamma rays - high-speed electron, very high energy, lightest mass, and greatest penetrating ability |