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Chem Test 1: Ch 3
Vocabulary Ch 3: Chemistry an Introduction Timberlake
| Question | Answer |
|---|---|
| Alkali Metal | Group 1 A, soft shiny with one valance electron (exclude Hydrogen) |
| Alkaline Earth Metals | Group 2A, 2 valence electrons |
| Atom | Smallest particle of element that retains its characteristics |
| Atomic Mass | weighted average mass of all isotopes |
| Amu | Atomic mass unit, used to measure atoms and subatomic particles |
| Atomic Number | Number of protons in an atom |
| Compound | Pure substance containing 2 or more elements, can be broken down by chemical process |
| Electron | Negatively charged particle, basically no mass, e- |
| Element | Pure substance that cannot be broken down by a chemical process |
| Energy Level | Group of electrons with similar energies |
| Group | Vertical Column, contains elements with similar physical and chemical properties |
| Group Number | Top of each group, indicates number of valence electrons |
| Halogens | Group 7A |
| Heterogeneous Mixture | Mixture that is not uniform |
| Homogeneous Mixture | Mixture that is uniform |
| Ionization Energy | Energy needed to remove least tightly bonded valence electron |
| Isotope | Atom with different mass number, same atomic number, but different physical properties |
| Mass Number | Total number of neutrons and protons in atom |
| Metal | Left side of periodic table, shiny, malleable, ductile, good conductor of heat and electricity |
| Metalloid | on zigzag line, properties of metals and non metals |
| Mixture | physical combination of 2 or more substances that don’t change their identities |
| Neutron | Mass: 1 amu, in nucleus, symbol: n |
| Noble Gas | Group 8A, generally un reactive and seldom combined with others |
| Nonmetal | Right side of periodic table, little or no luster, poor conductor |
| Nucleus | center of atom contains proton and neutron |
| Orbital | region around nucleus where electrons are found |
| Period | horizontal row of elements |
| Physical Properties | characteristics that can be observed or measured |
| Proton | mass: 1 amu, in nucleus, symbol: p or p+ |
| Pure substance | matter with fixed composition: elements and compounds |
| Valence Electrons | Electrons in outermost energy level of atom |