chemistry test 3

over ch 1-5

A branch of science that deals with the study of the composition, structure, and properties of matter and the changes that matter undergoes.

chemistry

apply principles of chemistry physics biology and math to solve problems in the manufacture of products.

chemical engineers

foundational to other areas of chemistry

physical chemistry

chem of living things

biochem

5 major branches of chemistry

physical, organic, inorganic, biochem,and analytical

systemic study of universe and how it works

science

involves simply recording how things are

descriptive

involves comparing observations to determine how and why they are different

comparative

orderly process scientists use by which they investigate the secrets of nature

scientific method

3 major steps of scientific process

HOE

artificial situation that more clearly shows how things happen

experiment

a specific suggestion about the outcome of a particular process or the effect of a particular cause.

prediction

factor observed or measured to determine the results of an experiment

dependent variable

what does every well-designed experiment involves what?

comparison groups that have different values of the independent variable

group in which the independent variable is absent

control group

rules of conduct that apply to a member of society or to someone in a particular vocation

ethics

a specific, empirical description of the way that some aspect of the universe consistently behaves

law

a general explanation of why some part of the universe behaves the way it does

theory

law that sates that events observed in the universe have rational causes; the same cause will always have the same effect because the universe is rational

principle of causality

anything that provides a partial representation of something else

model

4 limitations of science

scope, assumptions, bias, and approximations

use of science to solve practical problems

technology

3 main components of the engineering process

defining problem, designing a solution, and evaluating the solution

the minimum characteristics that a design must have to function at all

criteria

any characteristics required to solve the problem

constraints

giving up a characteristic that is less important for one that is more important

tradeoff

a model of the design that is used for testing

prototype

consistency or reproducibility of a measurement, closely related to a measurement’s uncertainty.

precision

the closeness of a measurement to the actual, exact value

accuracy

values obtained by counting or set by a definition

exact numbers

a collection of compatible, related units that can be used to measure various quantities

system of measurement

modification of the metric system with meticulously defined standards for all units

SI

standard SI unit of length

meter

most familiar metric unit of volume

liter

quantity of matter in an object

mass

force of gravity upon an object

weight

commonly used to measure mass

kilogram

measures compactness of matter

density

P= m/V

formula for density

property of an object that depends of the size or extent of the object

extensive property

quantities that do not depend on an object’s size

intensive property

which properties can be added

extensive

most common measure for temp in chemistry

degrees celsius

form the basis of the F.P.S (Farenheit scale)

freezing and boiling points of water

coldest possible temp

absolute 0

how to find celsius temp from kelvin

subtract 273.15 from the K temp

T_c=T_k - 273.15

formula to find celcius from kelvin

base unit of time

second

the time required for an atom of cesium -133 to vibrate a particular way 9,192,631,770 times

definition of a second according to SI

(____ given unit) ( ^{—new unit}/ _{—— given unit}) = ___new unit

dimensional analysis

based on the fact that every number can be expressed as a number between 1 and 10 multiplied by a power of 10

scientific notation

digits that are certain along with one uncertain digit

significant digits

any operation can be performed on one side of an equation as long as it is also performed on the other side

key to solving literal equations

anything that occupies space and has mass

matter

what is the most important factor when dealing with a single substance

temperature

characterized by a definite shape and volume

solid

point where the particles have enough kinetic energy to break loose from their rigid positions and form a liquid

melting point

point where the particles gain enough kinetic energy to break away from each other forming a gas

boiling point

a hot gas in which atoms are partially broken down to form charged particles

plasma

form of matter with unique properties that make it different from every other substance

substance

cannot be broken down into simpler substances by ordinary chemical means

elements

consists of pure substanaces that are incompletely mixed

heterogeneous

a homogeneous part of a system that is in contact with but physically distinct from other parts of a system that is in contact with but physically distinct from other parts of the system

phase

thought that particles had texture and that that was the reason for how they behaved, called them atomos

democritus

states that the masses of each element in a given compound always have the same ratio

law of definite composition

states that when two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element are in a ratio of a small whole numbers

law of multiple proportions

properties that describe a substance’s appearance

physical properties

can be measured without changing the identity or composition of the substance

physical properties

changes in the physical appearance of matter that do not change the identity or chemical composition of a substance

physical changes

may often be reversed by physical processes

physical changes

a change in which a substance becomes a different substance with a different composition and properties

chemical change

can only be reversed by other chemical changes

chemical change

observations which suggest that a chemical change has occurred

liberation or absorption of energy, distinct change in color, or formation of a gas,or precipitate,

distillation with very different boiling points

simple distillation

distillation with boiling points that are close together

fractional distillation

separation technique in which a sample is dissolved in hot solvent and then slowly cooled to precipitate

fractional crystallization

method used if the desired substance is less soluble in water or some other solvent that the impurity is

fractional crystallization

simplest forms of chromatography

paper chromatography

a group of separation techniques that are based on the different with each component in a mixture interacts with a stationary phase

chromatography

smaller particles of matter in an atom

subatomic particles

used electricity to decompose chemical compunds

sir humphry davy and michael faraday

proposed that units of electrical charge(-) are associated with atoms based on faraday’s work. he named these proposed particles electrons

George Stoney

the negatively charged electrical lead or electrode

cathode

positive electrode

anode

rays made of electrons that travel through a vacuum or near vacuum from a cathode to an anode

cathode rays

designed an improved cathode ray tube

sir william crookes

demonstrated that they are composed of negatively charged particles, electrons

j.j. Thomson

performed the oil-droplet experiment

robert millikin

negative cathode rays traveling toward the anode

canal rays

did the work that led to the discovery of positively charged particles

wihelm wien and j.j. thompson

“plum pudding model”

j.j. thompson

planetary model

rutherford

conclusively demonstrated the existence of a neutron

james chadwick

mostly empty space, with a small very dense nucleus containing positively charged protons and uncharged neutrons in the center

atom

type of particle of which protons and neutrons are formed

quarks

what determines the identity of an element

the number of protons in the nucleus

number of protons in the nucleus

atom’s atomic number

sum of number of protons and neutrons

mass number

nuclear particles

nucleons

atoms of the same element that differ in their mass numbers

isotopes