chem chp 1 & 2

book chapter and slide shows from clas

atoms

particle that are fundamental to building blocks of matter

molecule

specific geometrical arrangement of atoms

chemistry

science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules

hypothesis

tentative interpretation or explanation of the observations

experiment

highly controlled procedures designed to generate observations that confirm or refute a hypothesis

scientific law

brief statement that summarizes past observations and predicts future ones

scientific theory

model for way nature is and tries to explain not merely what nature does but why

atomic theory

matter is composed of atoms, and when combines mass is not lost

law of conservation of matter

in chemical reaction, matter is neither created nor destroyed

matter

anything that occupies space and has mass

substance

specific instance of matter

state

physical form of matter

composition

basic components that make matter up

crystalline solid

atoms or molecules are in patters with repeating order

amorphous solid

atoms and moleucles don’t have pattern or order

decanting

gradually pour solution from one container to another carful not to disturb sediment

distillation

action of purifying a liquid by a process of heating and cooling

volatile

when mixture of liquids have boiling temps, boil mixture to closest boiling point and let it evaporate and cool as filtered substance

filter

separate solid and liquid by filter paper

physical change

change that alters only the state or appearance

chemical change

change that alters the composition of matter

physical property

property that a substance displays with out changing its composition, “visual, senses”

chemical property

property that a substance displays only by changing its composition via chemical change

examples of physical change

odor, taste, color, appearence, MP, BP, density

examples of chemical change

corrosiveness, flammability, acidity, toxicity

energy

capacity to do work

work

action of force thru a distance

kinetic energy

energy associated with motion

potential energy

energy associated with its position and composition

thermal energy

energy associated with temperature of object

law of conservation of energy

energy is neither created nor destroyed

extensive property

matters how much is present

intensive property

does not matter how much is present

accuracy

how close are we to the expected result

precision

how close are all measurements

random error

error that has equal probability of being too high/low

systematic error

error that tends to repeatedly be either too high/low

dimensional analysis

solve problems by converting one unit to another

conversion factions

fractional quantity with units we are converting from on bottom and units we are converting to one top of equation

rounding rule

do not round until final step, if number is 5, round to get an even answer (ex: 1.2345 - 1.234)

qualitative

noting/describing how process happens

quantitative

measuring/quantifying something about process

falsifiable

hypothesis that can be confirmed or refuted by future investigation

LAW

summarizes a series of related observations

THEORY

gives underlying reasons for observations

normal science

data that is forced to fit into required theory

solid

atoms right next to each other, cannot pass by each other

liquid

atoms packed tight but can move freely

gas

atoms have a lot of space, compressible can force them into smaller space

pure substance

if composition of substance doesn’t vary

homogeneous

uniform thru out (sweet tea)

heterogeneous

not uniform (sand and water)

component

of pure substance can be atom or groups of atoms

mixture

composed of two or more components

element

substance that cannot be chemically broken down into simpler substances

compound

substance composed of two or more elements

chemical energy

type of potential energy that comes from electrostatic forces between charged particles composing the atoms and molecules

significant

all non zero digits are ___

significant

interior zeros are ____

not significant

leading zeros are ____

significant

trailing zeros after a decimal point are ____

significant

zeros before a decimal point and after a non zero number are ____

ambiguos

zeros between implied decimal point are ___

units

standard quantities used to specify measurements

volume

measurement of space

density

ratio of its mass to its volume (D=M/V)

law of definite proportions

applied to two or more samples of same compound and states that the ratio of one element to the other is always the same

law of multiple proportions

applies to two different compounds containing same two elements

radioactivity

emission of small energetic particles form more of certain unstable atoms

nerutrons

neutral particles with in nucleus mass of neutron is similar to a proton

isotopes

have same number of protons but neurons can be different

atomic number (Z)

number of protons in an atom’s nucleus

natural abundance of isotopes

number or probability that the sample has certain number of neutrons

ions

atoms that can lose or gain electrons and become charged particles

cations

positively charged ions

anions

negatively charged ions

periodic law

when elements are arranged in order of increasing mass, certain sets of properties recur periodically

metals

left side of PT, good conductors of heat and electricity can be made into sheets or wires, shiny, lose electrons when undergo chemical change

nonmetals

right side of PT, poor conductors of heat and metal, gain electrons when go under chemical reaction

metalloids

zig zig section in middle, mixed properties

atomic mass

PT is labeled left to right in increaseing ____ _____

family group

each column in PT

noble gases

unreactive, doesn’t combine with other elements

alkali metals

all reactive metals

alkali earth metals

fairly reactive

halogens

reactive nonmetals

molar mass

mass of one mole of atoms of an element