Final Exam - Physical Science Study Guide

J. J. Thompson

discovered the electron, Plum Pudding Model

Neils Bohr

his model shows electrons moving in energy levels displayed as concentric circles around the nucleus.

John Dalton

developed atomic theory

Earnest Rutherford

identified the nucleus in Gold Foil Experiment

element

pure substances consisting of only one type of atom (Magnesium)

compounds

pure substances made of two or more different elements chemically bonded as molecules (H2O)

mixtures

physical combination of two or more substances that are not chemically bonded (salt water)

physical properties

charactersitics that can be observed without changing the substance’s identity (color)

chemical properties

describe a substance’s ability to undergo changes that transform it into different substances

physical change

changes in form of state that do not create new substances (bending a paperclip)

chemicial changes

transformations that result in new substances, often indicated by bubbles, temperature change (reacting acid with a base)

exothermic reactions

release heat, causing the surroundings to get hot

endothermic reaction

absorbs heat

isotopes

Atoms of the same element with different numbers of neutrons.

ionic compounds

metal + nonmetal (no prefixes)

covalent compounds

nonmetal + nonmetal (prefixes)

synthesis

multiple reactants combine into one product

decomposition

one reacant breaks down into multiple products

single replacement

one element replaces another in a compound

double replacement

parts of two compounds switch places

combustion

A substance reacts with oxygen, often producing CO2​ and H2​O

kinetic energy

measured as temperature, when temperature is changing on a graph

phase change

indicated by flat lines, potential energy

hydrolysis

the decomposition of water, the chemical breakdown of a compound due to its reaction with water

acids

pH of less than 7

bases

pH of greater then 7

neurtal

pH of 7

cohesion

the attraction between water molecules

adhesion

the attraction between water molecules and other molecules

Specific heat capactiy

the amount of energy required to the tempeature of 1g by 1 degree Celsius

universal solvant

water is polar and can dissolve other things

surface tension

as the temperature decreases, the density decreases as well

capillary action

water can climb up a tube against gravity

product of acid and base reaction

when an acid and base react, they form water

first shell

2 electrons

what two structural features of water molecules determine the physical and chemical properties of water?

small molecules, uneven electron distribution resulting in polartiy

second shell

8 electrons

third shell

18 electrons

density

water is at its densist at 3 degrees, then the density begins to decrease