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7th MidRvw CBB 14-15
7th Grade Midterm Review Chemical Building Blocks Terms 2014-2015
Term | Definition |
---|---|
Protons | positively charged parts of an atom |
electrons | negatively charged parts of an atom |
neutrons | neutrally charged parts of an atom |
periodic table | a chart which lists all of the known elements |
Atom | The smallest unit of an element, the building block for all matter |
Physical Change | The change in a substance that does not change its identity. ex: tearing paper |
Volume | the amount of space that matter occupies. V=M/D. Units - cm3 or mL |
Solution | A well-mixed mixture. ex: Kool Aid |
Mass | a measure of how much matter is in an object. M=DxV. Units - gm |
Element | a substance that cannot be broken down into other substances by chemical or physical means |
Weight | the measure of the force of gravity on an object |
Compound | a substance that is made of two or more elements that are chemically combined |
Chemical Change | a change in which one or more substances combine or break apart to form new substances |
Mixture | two or more substances that are mixed, but not chemically combined |
Molecule | a combination of two or more atoms |
Density | the measurement of how much mass is contained in a given volume. D=M/V. Units - gm/cm3 |
Reactivity | DECREASES across periods from left to right. Group 1 are MOST reactive. Group 18 are NONreactive |
Magnetic properties | DECREASE across periods from left to right. METALS are on the LEFT side of the PT, NON METALS are on the RIGHT side of the PT |
Group/Family | The elements down the columns of the PT; they share similar properties. |
Periods | The elements across the rows of the PT; their properties change in a predictable pattern. |