Chapter 3 & 4-Matter, Philosophers, and Isotopes Flashcards
Matter
anything with mass that takes up space
Substance/Pure Substance
Matter with a uniform and unchanging composition
Has the same composition no matter where it’s taken from
ex. salt, pure water
Seawater and tap water are not pure substances since they can be different depending on where they are from
States of Matter
Solid
Liquid
Gas
Physical Properties of Matter
characteristic of matter that can be observed or measured without changing the sample’s composition; describe pure substances
ex. density, color, odor, hardness, melting/boiling point
Extensive and intensive properties
1) Extensive properties: dependent on the amount of substance present
ex. mass
2) Intensive properties: independent on the amount of substance present
ex. density
Chemical Properties of Matter
ability or inability of a substance to combine with or change into one or more other substances
Physical Change
change which alters a substance w/out changing the composition
ex. cutting a block of wood
Phase Change
transition of one state of matter to another
Chemical Change/Reaction
when one or more substances change into new substances with new compositions and properties (starting substances are reactants and new substances are products)
reactants and products have different properties
Law of Conservation of Mass
Mass neither created nor destroyed during CHEMICAL reactions
Mass(reactants)=mass(products)
Solid
definite shape and volume
Liquid
takes shape of container
definite volume
Gas
indefinite shape
indefinite volume
Solid –> Liquid
melting
liquid –> gas
vaporization
liquid –> solid
freezing
gas –> liquid
condensation
solid –> gas
sublimation
gas –> solid
deposition
How do you know that a chemical reactions has occurred?
- Light produced
- Heat produced
- Color changes
- Smell changes
- A property changes (ex. mass, density, etc)
- Gas forms (ex. vinegar and baking soda)
- Precipitate Forms
Law of Definite Proportions
a compound will have a definite ratio by mass of the elements that are in it
Law of Multiple Proportions
when different compounds are formed by the same combo of elements, the elements can combine in different whole # ratios
Solution
homogeneous mixtures
Element
pure substance that can’t be separated into simpler substances by physical or chemical means
Purifying Mixtures
filtration centrifugation crystallization distillation using a funnel chromatography
filtration
separates suspensions (heterogeneous mixtures)
separates liquid from solids
pour mixture through funnel with a piece of filter paper
liquid that passes through=filtrate
centrifugation
separating small amounts of suspension
suspension put into centrifuge tubes and spin around in a centrifuge
fast spinning motion forces the solid to the sink to bottom of tube
Crystallization
forming crystals
hot concentrated solution is cooled (solvents cant hold all dissolved solids when cooled)
solubility differences separate one material from another
Distillation
separate solid from a liquid, or 2 miscible liquids from each other
mixture heated and one liquid vaporizes (vapor made back to liquid with condenser)-differences in boiling points
can separate homogeneous mixtures
Using a separating funnel
immiscible liquids
liquid with higher density forms lowest layer
chromatography
paper chromatography, 2 factors:
- absorption of substance on paper
- solubility of substance in solvent
Democritus
proposed that matter was composed of small indivisible particles called atoms
believed that there was a different atom for each material
Dalton
matter composed of atoms
atoms of same element are identical
atom is the smallest particle and can’t be broken down
elements combine in mall, whole # ratios to form compounds
atoms break apart, combine, or rearrange to form compounds
Thomson
discovered e’s: determined it’s charge to mass ratio
plum pudding/choco chip cookie dough model
determined proton’s mass
discovered isotopes
Rutherford
Gold Foil Experiment
nucleus was a small dense core inside the atom mostly of empty space
nucleus is a proton which balances the negative e’s
Chadwick
neutrons
Millikan
oil drop experiment: determined e’s charge
Bohr
e’s travel in definite energy levels around nucleus
Planck
electromagnetic energy’s radiated in small packets called quanta
of p’s = __________ = # of ___
atomic number
electrons
Atomic mass
average of all of the elements isotopes
Mass Number
# of protons + # of neutrons atomic mass rounded to the nearest whole #
How to write elements in symbolic notation
(Look at Skitch)
Isotope
same # of p’s, different # of neutrons
Which isotope (ligher or heavier) reacts faster in chemical reactions?
lighter
3 Types of Radiation
- Alpha Decay
- Beta
- Gamma Ray
nuclear reaction
reactions that involves a change in the nucleus
radioactivity
process by which some substances spontaneously emit radiation
Alpha Decay, Beta, and Gamma Ray
look at Skitch
Vapor
gas of a substance that is a solid or liquid at room temp
ex. steam
Mixture
combo of 2 or more pure substances in which the substances retain its individual chemical properties
Types of solutions
gas-gas liquid-liquid solid-solid gas-liquid solid-liquid solid-gas
Alloy
homogeneous mixture of metals
OR
mixture of metal and a nonmetal in which the metal is the major component
