Unit 3: Matter and States of Matter Flashcards
Matter
the MATERIAL that makes up a substance
(makes up things we use everyday ex. water and wood)
Pure Substances
matter with a SPECIFIC composition
composed of only one type of atom or molecule
ex) element or compound
Element
a pure substance that contains only ONE atom
Compounds
contains two or more elements in a definite ratio
Note about elements in a compound
properties of compound don’t always match the properties of the element
Mixtures
two or more substances physically combined, different proportions, can be separated by physical methods
Physical Separation of A Mixture
Involves only A PHYSICAL CHANGER
ex.) Occurs when is pasta and water are separated with a strainer.
Homogenous mixtures
composition is uniform throughout and different parts of the mixture are not visible
ex) brass (copper and zinc)
Heterogenous mixtures
composition is NOT uniform and the different parts of the mixture are visible
ex) water and copper
Methods of separating mixtures (7)
Evaporation, filtration, paper chromatography, distillation, separating funnel, using a magnet, decanting
Evaporation
process by which water changes from a liquid to a gas state
Used to separate a solid from a liquid in which it can dissolve.
Filtration
used to to separate an insoluble solid from a liquid
Chromatography
used to separate a mixture of colors
often used in the food industry
Fractional Distillation
Used to separate mixtures of liquids with different boiling points.
Separating Funnel
used for separating mixtures of liquids that do NOT dissolve very well in each other (immiscible liquids) and have unequal densities
ex) oil and water
Using a Magnet
used for separating mixtures of solids when one of the solids has magnetic properties
Decanting
used for separating a solid from a liquid
pouring liquid (supernate) from the mixture without disturbing the solid residue
Physical Change
identity and composition of the substance do not change
and
The state can change or the material can be torn into smaller pieces
Chemical Change
Reacting substances form new substances with different compositions and properties
a chemical reaction takes place
Examples of chemical changes
rusting nail, bleaching a stain, burning a log, tarnishing silver, fermenting grapes, souring of milk
Examples of physical changes
melting ice, boiling water, sawing a log in half, tearing paper, breaking a glass, pouring milk
Four things that happen in a chemical reaction
In a chemical reaction…
chemical change produces one or more new substances
change in the composition of one or more substances
old bonds are broken, new bonds are formed
atoms in the reactants are rearranged to form one or more different substances
SIGNS OF A CHEMICAL REACTION (5)
- Color Change
- Bubbles Forming
- Precipitate Forming
- Smell (sometimes)
- Temperature Change
Precipitate
insoluble that settles at the bottom of test tube (usually a different color)
Characteristics of a solid
- definite shape
- definite volume
- particles that are close together in a fixed arrangement
- particles that move very slowly
Characteristics of a liquid
- indefinite shape BUT definite volume
- same shape as container
- particles that are close together, but not mobile
- particles that move slowly (not very)
Characteristics of a gas
- indefinite shape
- indefinite volume
- same shape and volume as their container
- particles are far apart
- particles move very fast
What bonds are between water molecules?
hydrogen bonds
Condensation
heat released
gas –> liquid
Freezing
heat released
liquid —> solid
Deposition
heat released
gas —> solid
Vaporization
heat absorbed
liquid —> gas
Melting
heat absorbed
solid —> liquid
sublimation
heat absorbed
solid —> gas
Heating Curve
shows phase changes as a solid is heated
uses sloped lines to show an increase in temperature
uses plateaus to indicate a change of state (during plateaus temperature does not increase)
