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Atoms and Elements
Chapter 4 terms and definitions
Term | Definition |
---|---|
Atom | The smallest unit of an element that retains the properties of the element. |
Atomic Theory | The development of our understanding of the atom and all that goes with it. |
Subatomic | Anything that is smaller than an atom. |
Nucleus | The central core of an atom that contains both protons and neutrons. |
Proton | A small, positively charged particle found in the nucleus of an atom. |
Electron | A tiny, negatively charged particle that moves around the outside of the nucleus. |
Neutron | A small particle found in the nucleus that has no charge. |
Charge | A physical property of matter that determines what a subatomic particle will do. |
Atomic Number | A number used to identify an element and is equal to the number of protons in an atom. |
Isotope | Atoms with the same number of protons but a different number of neutrons than expected. |
Periods | Horizontal rows on the periodic table. |
Groups | Vertical columns on the periodic table. |
Chemical Symbol | A one to three letter abbreviation for an element's name which is universally understood. |
Fusion | The process through which new elements are created. |
Radioactivity | The spontaneous emission of radiation by an unstable nucleus. |
Alpha Decay | Positively charged particles that contain two protons and two neutrons. |
Beta Decay | Negatively charged particles that are made of fast moving electrons, given off during radioactive decay. |
Gamma Waves | Neutral waves of high energy and the most powerful form of radioactive decay. |