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Chem chapter 2, vocb
September 17th-Oct. 3rd, 2012
Question | Answer |
---|---|
Matter | anything that has mass & takes up space |
Mass | amount of matter in an object (depending on gravity.) |
Atoms | tiny building blocks that matter is composed of |
Elements | simplest form of matter |
Compounds | 2 or more different types of atoms are chemically bond together |
Molecules | particles that compose a compound; made up of 2 or more different kinds of atoms stuck together by chemical bonds |
what are physical properties that can identify a substance? | odor, color, melting point, mass, boiling point, density, volume |
chemical properties | pertain to the ability of a substance to form a new substance by reacting with other substance |
physical change | do not involve a change in the idenity of the substance |
chemical change | involve reactions in which one or more substances are converted to new substances |
phase change | all phase changes are physical changes. only involve a change in the energy and speed of the particles. Particles retain their idenity |
chemical | when one or more substances are changed into new substances |
reactants | stuff you start with |
products | what you make. *products have new properties |
solid | matter that can not flow and has definite volume |
liquid | definite volume but takes the shape of its container ( flow) |
gas | no definite volume or definite shape and can flow |
denisty | ice floats, because of a phase change |
volume | ice expands ( the expansion of water when it freezes is a major source of weathering rocks; they crack and break apart) ; because of a phase change |
electronolysis | H20 --> H2 + O2 H2O(L) --> H2O(g) |
phase changes | are all physical; only involve a change in the energy& speed of particles; particles retain their idenity |
mixtures | made up of two substances |
heterogeneous | mixture is not the same from place to place ex. chocolate chip cookies, gravel, trail mix |
homogeneous | same composition throughout ex. kool-aid, air |
solution | homogeneous mixtures; mixed by molecule to molecule; can occur between any state of matter |
solute | substance that is known to dissolve |
solvent | substance that which the solute dissolves |
elements | simplest kind of matter; cannot be broken down; all one kind of atom |
compounds | substances that can be broken down by chemical methods |
molecules | two or more atoms ( smallest piece of a compound) |
periodic table | columns referred to as groups; rows referred to as periods; 90 natural occurring elements(BOLD) *blue letters= liquid at room temperature **red letters= gas at room temperature |
properties of metal | conductors of heat & electricity; mallebe ( dent) ; ductile ( pull-able ( stretchy)) ; high tensile strength; luster ( shine ( nice surface)) |
properties of nonmetals | poor conductors of heat & electricity; tend to be brittle; many nonmetals are gases at room temperature |
properties of metallbids | both metals & nonmetals; metalloids more brittle than metals, less brittle than most nonmetallic solids; semiconductors of electricity; some metalloids posses metallic luster |
silicon | metallic luster; brittle like a nonmetal; semiconductor of electricity |
chemical change | a change in which one or more substances are converted into different substances ( heat & light are often evidence of a chemical change) |
chemical reaction | when one or more substances are changed into a new substance |
reactants | stuff you start a chemical reaction with |
products | what you make after finishing the chemical reaction |
indications of a chemical change | energy absorbed or released; color change; odor change; precipitate - solid that separates from the solution |
chemical property | pertains to substances ability to react with other substances |