scie nce schem

compound

a substance made up of two or more atoms chemically bonded together in fixed ratios

isotope

an atom of a particular element with the same number of protons but different number of neutrons

mass

the amount of matter in an object

matter

physical substance that has mass and takes up space

pure substance

a substance that contains only one type of particle

covalent bond

a bond between non metal elements where two atoms share one or more pairs of valence electrons

ion

a charged atom due to losing or gaining valence elctrons

ionic bond

a bond between a metal and non metal through the transfer of valence electrons, resulting in a postively charged cation and negatively charged anion

lattice

an interlaced structure or pattern

metallic bond

a strong attraction between positive metal ions and free moving electrons

molecule

two or more atoms held together by chemical bonds, forming the smallest unit of a substance that retains all its chemical properties

valency

an atom’s power to combine with other atoms

polyatomic ions

two or more ions bonded together and acting as a single charged unit

concentration

the number of particles in a given volume

kinetic energy

energy of motion

activation energy

the energy required to start a reaction

catalyst

substance that increases the rate of a chemical reaction without itself being used up

enzyme

a biological catalyst that increases the rate of reactions in cells

surface area

the area of the outermost layer of an object

rate of reaction

how quickly reactants are converted into products

5 influences on reaction rates

concentration, temperature, pressure, surface area, catalysts

increasing concentration affect on reaction rate

causes more reactant particles moving around to increase the frequency of successful collisions, increasing reaction rate

increasing temperature affect on reaction rate

increases the speed and energy of reactant particles, causing more collisions per second with greater force to rearrange and form products, increasing reaction rate

increasing pressure affect on reaction rate

decreases volume, causing more collisions between particles, increasing reaction rate

increasing surface area affect on reaction rate

causes an increase in the frequency of successful collisions, increasing reaction rate

catalyst affect on reaction rate

catalysts increases reaction rate by providing an alternative reaction pathway using less activation energy

mono, di, tri, tetra, penta, hexa, hepta, octa

1, 2 , 3, 4, 5 , 6, 7, 8

examples of metallic bonds

copper, iron, sodium, all metals

examples of covalent bonds

carbon dioxide, hydrogen oxide, methane

examples of ionic bonds

potassium chloride, copper sulfate, calcium carbonate