Justin Bieber says: "We're
classifying matter"
Matter is anything that has mass and takes up space. Matter ca
be made up of particles called atoms. It can exist as a solid,
liquid, gas, or plasma.
All matter has both physical and chemical properties.
Physical Properties
·Can be observed without changing the identity of the matter.
What's it mean by "identity"?
The identity is the molecular formula of the matter. It is the stuff that makes up the
matter. Water is H2O whether it's a solid, liquid, or a gas
Examples: melting, freezing, boiling, solubility and density
Density
·Describes the relationship between mass and volume
m
v
The density of a solid
is expressed in
The density of a liquid is
expressed in
g/ml
Remember: 1 cm3 = 1ml
g/cm3
Chemical Properties
·Describe a substance based on its ability to change into a new
substance with different properties.
What does this mean?
It means that when observing this property it changes the identity of the matter.
When or 2 or more substances react they change into new substance with new
properties
Examples: Flammability, reactivity, rusting, tarnishing,
patina
Characteristics Properties
A property that is unique to each substance. They can be
used to identify a substance.
It does NOT depend on the amount of the material or the
element.
They include freezing, boiling, or melting points, density, color, reactivity, and
solubility.
Physical and Chemical Changes
A physical change affects one or more physical properties. It does not change its
identity.
·Melting gold or butter
·Breaking a pencil in half
·Any change of state (boiling, freezing, evaporating, etc.)
·A chemical change occurs when one or more substance
change into new substances with different properties.
Burning (flammability)
Reactivity
A chemical change cannot be undone by physical means but they can sometimes be
undone by another chemical reaction
link
Physical or Chemical Changes
Physical and Chemical
A candle?
Elements, Compounds, and Mixtures
http://my.hrw.com/sh/hp1/0030724929/student/ch04/sec01/qc01/hp104_01_q01fs.htm
An element is a pure substance that cannot be separated into simpler
substances by physical and chemicals means.
Elements are identified by the nubmer of protons in the nucleus
0
A compound is a pure substance that is
composed of two or more elements that are
chemically combined in a specific ratio.
http://my.hrw.com/sh/hp1/0030724929/student/ch04/sec02/qc01/hp104_02_q01fs.htm
Pure Substance is a substance in which there is only one type
of material
Example: elements or compounds
Mixtures are a combination of 2 or more substances that are
NOT chemically combined. They can be separated by
chemical means.
Chicken Noodle soup is an example because the pieces of
chicken can be separated from the soup by physical means.
Pizza is a mixture as well.
Can you have different types of mixtures?
Yes!!!! But how are we going to classify them?
Scientists separate mixtures into 2 categories: Homogeneous or Heterogeneous
Homogeneous Mixtures
Homogeneous mixtures are combinations of matter where the particles are too small to be
seen and they are spread out evenly throughout the mixture.
Light can pass through a homogeneous mixture
because the particles are too small to scatter
the light.
Solutions are homogeneous mixtures---a mixture that
appears to be a single substance but it's really made of 2
or more materials distributed evenly amongst each other.
Solutions are made up of 2
parts:
The solute--the stuff
dissolved
The solvent- the stuff the
solute is dissolved in
he solute is dissolved in.
Solubility is the ability to dissolve a substance into a solution.
For example: sugar and salt can be dissolved into water so they have solubility.
All solutions have solubility and concentrations!
Concentration is the actual amount of solute dissolved in the solvent. It is measured in g/ml.
Types of solutions:
·gas in a gas (air)
·gas in a liquid (soda)
·liquid in a liquid (hydrogen peroxide)
·solid in a liquid (kool-aid)
·solid in a solid (metal alloys)
Heterogeneous mixtures
Heterogeneous mixtures are mixtures that contain particles that
are large enough to be seen and too heavy to remain suspended
in the solvent.
For example: Vinegarettes and salad dressings, sand and
gravel mixtures, a snow globe
Suspensions are heterogeneous mixtures in which the particles
are so large that they eventually will settle out (fall to the bottom)
Sand and water, salad dressings,
muddy water
The particles are large enough to scatter
the light
Matter
Mixture
Pure
Substance
Elements
Compounds
Homogeneous
Solutions
Heterogeneous
Suspensions
3 Major categories of Elements
http://my.hrw.com/sh/hp1/0030724929/student/ch04/sec01/qc03/hp104_01_q03fs.htm
Metal--malleable (can be flattened into sheets), ductile (can be made
into wires), shiny, good conductors of heat and electricity.
Nonmetal-- dull, poor conductors of thermal or electrical energy
(easily break)
Metalloid--semiconductors, have properties of both metals and
nonmetals, only conduct electrical energy at high temperatures.