Embed Size (px)
Citation preview
MATTER
Chapter 2.1Chapter 2.1
Matter
Anything that has Anything that has mass and occupies mass and occupies space.space.
ChemistryChemistry is the study is the study of matter and how it of matter and how it changes.changes.
Pure Substances
Uniform and definite Uniform and definite compositioncomposition
Formed and separated Formed and separated chemicallychemically
2 types Elements & compounds2 types Elements & compounds
Pure Substance
ElementsElements – a substance that cannot be – a substance that cannot be broken down into smaller substances.broken down into smaller substances. AtomsAtoms – smallest particle that has – smallest particle that has
properties of an element. properties of an element. Both expressed by symbolsBoth expressed by symbols
Compounds
CompoundsCompounds – a substance – a substance formed when two or more formed when two or more elements elements chemicallychemically combine combine together.together.
Molecules
The smallest unit of a The smallest unit of a substance that exhibits all of substance that exhibits all of the properties characteristic of the properties characteristic of that substance (compound)that substance (compound)..
Two or more atoms chemically Two or more atoms chemically combinedcombined
Chemical Formulas
Ex. CEx. C1616HH1010NN22OO22
Mixtures
A physical combination of more than one substance.
(Two Types)
Homogeneous Mixtures
SolutionsSame throughout (miscible)
ex: flat soda, salt water, black coffee
Heterogeneous Mixtures
Not uniformly mixed, different parts
Substances that need to be shaken
ex: noodle soup, granite
Classifying Liquid Mixtures:
miscible-dissolve into each other
immiscible-don’t mix into each other. You can see layers
ex: oil and water.
Liquids Mix with Gas
Can you think of a very common example???
MATTER AND ENERGY
2.2
Kinetic Theory
1. All matter is made of atoms and molecules that act like tiny particles.
Kinetic Theory
2.These tiny particles are always in motion. The higher the temperature, the faster the particles move.
Kinetic Theory
3. At the same temperature, heavier particles move slower than lighter particles.
Phases/States of MatterGasGasliquidliquidsolidsolidplasmaplasma
States of Matter - Gases
no definite shape.no definite volume.easy to compress.most random arrangement of particles.
Most spread out.
Gases
Property of gases is called pressure. the force exerted per unit area of a surface
Liquids
Definite volumeno definite shape (takes shape of container)Difficult to compressdisorderly arrangement on particles
Close together
Liquids
Property of Liquids is called viscosity. the resistance of a fluid to flow
Solids
Definite shapeDefinite volumeDifficult to compressOrderly arrangement of particles close together
Smallest amount of movement of particles.
Energy
The ability to change state or move matter.
Changing state does not change composition of the substance
liquid gassolid
Changes of State
Law of conservation of matter (mass)
Matter (mass) cannot be created or destroyed.
It only changes its state or rearranges its atoms.
Law of conservation of energy
Energy cannot be created or destroyed.
It converts from one form to another during chemical or physical changes.
PROPERTIES OF MATTER
2.3
Physical Property
A characteristic of a substance that can be observed or measured without changing the composition of the substance.
Physical Property
Melting and freezing points.Solubility
Dissolving of a solid into a liquid.
Density
Why do some things float while others sink?
Density
mass/volume (D=m/V)UNITS:mass – (g)Volume – (mL) or (cm3)density – (g/mL) or (g/cm3)
Density
Buoyancy-The force with which a more dense fluid pushes a less dense substance upward.
ex. floating ice.
Example
An unknown metal is measured to be 36 grams. What is it’s density if it has a volume of 15.5 cm3?
D=m/v d= 36 g/ 15.5 cm3
D = 2.322 g/cm3
Last point is sig. figs. 2.3 g/cm3
+1+1
+1 +1
+1
Chemical Properties
The way a substance reacts with others to form new substances with different properties.
Chemical Properties
FlamabilityReactivitycorrosion
Physical Changes
A change in the physical form or properties of a substance that occurs without a change in composition.
Chemical Change
A change that occurs when a substance changes composition by forming one or more new substances.
Chemical Change
4 signs:Evolution heat or lightColor changeFormation of gasFormation of a precipitate (solid residue)
