Unit 1 & 2 Test

magnitude

Prefixes give the _________ of the measurement.

10^6

mega-

10³

kilo-

10^-1

deci-

10^-2

centi-

10^-3

milli-

0 kelvin

The point where there is virtually no particle motion or kkinetic energy, also known as absolute zero.

derived units

defined by a combination of base units (not SI)

independant

A base unit is ___________ of other units.

273.15

To convert from Celsius to Kelvin, add ___.__.

m/v

D = _______

accuracy

The closeness to an accepted value.

precision

The closeness of data to each other

error

The difference between an experimental value and an accepted value.

-20

Accepted value = 90, but estimate = 70. What is the error?

percent error

100(|error|/accepted value)

are

zeros between non-zeros ___ sig figs

are

zeros right of the decimal point ___ sig figs

are not

anything you can remove in scientific notation ___ sig figs

solids, liquids

______ and _______ resist compression.

sublimation

solid to gas

deposition

gas to solid

ionization

gas to plasma

plasma

gas without electrons (ionized)

capash

capeesh?

extensive property

An __________ __________ is dependant on the amount of substance present, such as mass, length, and volume.

intensive property

An ____________ ___________ is independant of the amount of substance present, such as density.

extensive properties

• ductility

• entropy

• weight

• heaviness

• electrical charge

• energy

• momentum

• concentration

• chemical potential

intensive properties

• density

• magnetic field

• elasticity

• melting point

• viscosity

• electrical resistivity

sums

When rounding ____ or differences, the number of sig figs to the right of the decimal equals the limiting term’s number of decimal point places.

Solid

Definite shape and volume; resists compression.

Liquid

Indefinite shape and constant volume; resists compression.

Vapor

Form of a substance (gas) that is normally a liquid or gas at the given temperature.

Gas

Fills the entire container; highly compressible.

Intermolecular

______________ distance is the distance between particles.

Plasma

A gas without electrons (ionized).

Physical

________ properties can be observed/measured without changing the sample’s composition.

Physical properties

Boiling point, melting point, odor, density, viscosity, specific heat.

Viscosity

A physical property that means the resistance of flow.

Chemical

________ properties are the ability of substances to combine with or change into one or more other substances.

Chemical changes

Decomposing, rusting, exploding, burning, oxidizing.

Physical changes

Ripping, cutting, smashing.

Extensive

___________ properties are dependent on the amount of a substance present.

Intensive

_______ properties are independent of the amount of a substance present.

Extensive properties

Volume, ductility, entropy, chemical potential, weight, heaviness, length, mass, number of molecules, electrical charge, energy, momentum, concentration.

Intensive properties

Density, magnetic field, malleability, elasticity, melting point, viscosity, electrical resistivity.

Phase change

The transition of matter from one state to another.

Law of conservation of mass

Mass is neither created nor destroyed in a chemical reaction. It is conserved. The mass of the reactants is equal to the mass of the products.

Mixture

A combination of two or more pure substances in which each pure substance retains its individual chemical properties

Heterogeneous

______________ mixtures contain individual substances that remain distinct.

Homogeneous

_____________ mixtures have a composition that is constant throughout.

Solution

Also known as a homogeneous mixture.

Colloids

Heterogeneous mixtures of intermediate sized particles (between 1 — 1000 nm) and do not settle out.

Suspension

Mixture containing particles that settle out if left undisturbed.

Filtration

A separation technique that uses a porous barrier to separate solid from liquid in a heterogeneous mixture.

Distillation

A separation technique for homogeneous mixtures based on the differences in boiling points of substances.

Crystalization

A separation technique for homogeneous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substances.

Sublimation

The process of a solid changing directly to gas, which can be used to separate mixtures of solids when one sublimates and the other doesn’t.

Chromatography

A separation technique that separates the components of a mixtures on the tendency of each to travel across the surface of another material.

Element

A pure substance that can’t be separated into simpler substances by physical or chemical means.

Compound

Made up of two or more elements combined chemically (table salt and water).

Colloid

________ examples are blood, milk, and gelatin.

Orange juice

Example of a suspension.

Electrolysis

SI base units

• seconds

• meters

• grams

• Kelvin

• mole

• ampere

• candela

92

__ elements occur naturally on Earth

law of definite proportions

a compound is always composed of the same elements in the same proportion by mass, no matter the size of the sample

law of multiple proportions

when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in whole number ratios

percent by mass

the ratio of the mass of each element to the total mass of the compound expressed as a percentage

• 100(mass of element/mass of compound)

Dalton’s atomic theory

easily explains the conservation of mass in a reaction as the result of a combination, separation, or rearrangement of atoms

Dalton

John ______:

• atoms are indivisible and indestructible

• matter is composed of small articles called atoms

• atoms in an element have the same size, mass, and chemical proporties

• atoms differ by element

• different atoms combine in whole number ratios to form compounds

atom

the smallest particle of an element that retains the properties of the element

JJ Thompson

man who created the cathode ray tube and discovered electrons

cathode ray

a ray of radiation that travels from the cathode to the anode when an electronic charge is applied (a stream of particles carrying a negative charge)

electrons

particles carrying negative charge

Robert Milkan

man who used the oil drop apparatus to determine the charge of an electron (coulombs)

plum pudding

JJ Thompson’s ____ _______ model of the atom states that the atom is a uniform, positively charged sphere that contains electrons

neutral

matter is _______

isotope

if the number of protons ≠ number of electrons, then the matter is an ________

Rutherford

studied how positively charged alpha particles interacted with solid matter using gold foil

• atoms are mostly empty space

• if they pass through, they go between the nucleus and electronic field

• opposite charges attract

nucleus

a dense region in the center of an atom that contains almost all of the positive charge and almost all of the atom’s mass