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7 CK Atomic Struct
7th CK SCI Atomic Structure COMPLETE
| Term | Definition |
|---|---|
| amu | Atomic Mass Unit, the unit used to weigh subatomic particles |
| Atom | the smallest piece of matter |
| Atomic mass | the average of all the mass numbers of all the isotopes of an element that occurs in nature |
| Atomic number | the number of protons in the nucleus of an atom |
| Corpuscle | negative subatomic particle in the atom discovered by J.J. Thomson; today it is known as an electron |
| Electron cloud | the area surrounding the nucleus where electrons are found |
| Element | the simplest pure substance |
| Indirect evidence | evidence that is gained based on observation |
| Isotope | an atom of a given element with a different number of neutrons than protons |
| Mass number | the sum of the number of protons and neutrons contained in an atom’s nucleus |
| Matter | anything with mass and volume |
| Molecule | two or more atoms chemically bonded together |
| Neutron | subatomic particle with no charge located in the nucleus of the atom |
| Nucleus | the center of positive charge in the nucleus; discovered by Ernest Rutherford |
| Proton | subatomic particle with a positive charge located in the nucleus of the atom |
| Pure substance | a substance in which all particles are alike |
| Subatomic particle | particle smaller that the atom |