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S8P1.a
Distinguish between...
Term | Definition |
---|---|
Atom | the smallest unit of an element that maintains the properties of that element. |
Element | A substance that cannot be broken down or separated into simpler substances by chemical mean. |
nucleus | in physical science, an atoms central region, which is made up of protons and neutrons. |
proton | a substance particle that has a positive charge and thats found in the nucleus of an atom. |
neutron | a substance particle that has no charge and that is found in the nucleus of an atom. |
electron | a substance particle that has a negative charge |
atomic number | the number of protons in a nucleus of an atom; the atomic number is the same for atoms of an element. |
neutral | having no overall change |
atomic mass | the mass expressed of an atom in atomic mass units. |
chemical symbol | one of two letter code that represents an element |
pure substance | a sample of matter either single element or a single compound, that was definite chemical & physical properties. |
compound | a substance made up of atoms of two or more different elements joined by chemical bonds |
molecule | the smallest unit of substance that keeps all of the physical and chemical properties of that substance., |
chemical formula | a combination of symbols and number to represent a substance |
subscript | a small number written to the right and slightly below a chemical symbol to tell the number of atoms of the element in the substance. |
mixture | a combination of two or more substance that are not chemically combined. |
state of matter | the physical forms of matter, which include solid, liquid, & gas. |
solid | the state of matter in which the volume and shape of a substance are fixed |
liquid | the state of matter that has definite volume but not a definite shape. |
gas | a form of matter that does not have a definite volume or shape |
melting point | temperature at which a solid changes into a liquid |
vaporization | process in which a liquid changes into a gas |
boiling point | temperature at which a liquid vaporizes and changes into a gas |
condensation | the change of state from gas to liquid |
freezing point | temperature at which a liquid changes into a solid |
sublimation | the process in which a solid changes directly into a gas |
phase-change diagram | drawing that shows the relationships among temperature and changes of state |
plasm | a state of matter that forms when temperatures are high enough to completely remove electrons from the atoms to which they were bound |
physical property | a characteristic of a substances that does not involve a chemical change, such as density, color, or hardness. |
density | the ration of the mass of substances the variable of the substance |
chemical property | a property of matter that describes a substances to the volume of a substance |
physical change | a change of matter from to another without a change in chemical properties |
chemical change | a change that occurs when one or more substances change into entirely new substances with different properties |
chemical reaction | the process by which one or more substances change to produce one or more substances |
precipitate | a solid thats produced as a result of a chemical reaction |
combustion reaction | a chemical reaction that occurs when oxygen combines with another substance |
periodic table | a chart that organizes information about all of the known elements according to their properies |
period | in chemistry, a horizontal row of elements in the periodic table |
group | a vertical column of elements in the period table ; elements a group share chemical properties |
valence electrons | an electron that is found in the out most shell of an atom and that determines the atoms chemical properties |
reactivity | describes how likely an element is to form bonds with other elements |
metalloid | elements that have properties of both metals and non metals |
inert | unable to react chemically under normal subtances |
law of conservation of matter | states that during chemical reaction, matter cannot be created or destroyed, it will only change from one form to another |
reactant | a substance of molecule that participates in a chemical reaction |
product | a substance that forms in a chemical reaction |
coefficient | a number written before a chemical formula which shows how many molecules of a compound are present |