Unit One Flashcards
What makes a good measurement
Uncertainty
Add units
Numbers themselves
When is data accurate
“Right”
When is data precise
“Consistent”
What is goal when getting data
First precision then accuracy
What are the hottest and coldest parts of a flame
Hottest on top of inner cone
Coldest very bottom
What makes a good experiment
Controlled variable
Independent and dependent variables
Repeatable/detailed
How do we express uncertainty
Significant figures and calculating extra decimal
All non zero numbers are or aren’t sig figs
Are significant
Zeros sandwiched in between sig gigs are or aren’t significant
Significant
Leading zeros before sig figs are or aren’t sig figs
Are not sig figs
Trailing zeros with or without decimal, sig or no?
With decimal yes sig
No decimal not sig
Counting number sig or no
Have infinite number of sig figs, like 20 people
To solve conversion use
Dimensional analysis
Conversion factor
Ratio or fraction relating or connecting two different units
Conversion unit problem pieces
Unknown amount and units
Initial amount and units
Conversion factor
Father of modern chemistry
Antoine Lavoisier
Law of conservation of mass
Lavoisiers conclusions
Mass can not be created or destroyed
Matter
Anything with mass and volume
Substance
Form of matter with uniform and unchanging composition
Filtration
Seperate a solids from liquids by using a porous barrier
Distillation
Separated substances on the basis of the boiling points of the substances
Crystallization
Separates by formation of solid, pure particles from a solution
Chromatography
Seperate a substances based on their movement through a special paper
Horizontal rows on periodic table
Periods
Vertical rows on periodic table
Group or families
State of matter
Solid, liquid, gas
Physical property
Characteristic observed or measured without changing sample composition.
Density, color, odor, hardness, melting point are all examples of what
Physical properties
Physical properties have two types that are?
Extensive properties and intensive properties
What are extensive properties
Dependent on the amount of substance present
Ex: mass length volume
What are intensive properties
Independent on the amount of substance present, ex density
Chemical properties
The ability of a substance to combine with or change into one or more other substances, or in ability to
Iron forming rust when combine with oxygen is what
A chemical property
Why is it important to state specific conditions such as temp and pressure under which observations are made?
Because both physical and chemical properties depend on these conditions
Physical change
Alters a substance without changing its composition
Foil going from smooth sheet to crumpled ball is
A physical change
Phase change
Transition of matter from one state to another
Chemical change
Process in which One or more substances changing into new substance with new properties and composition
Matter than can’t be physically seperated
Pure substance
Compound
A chemical combination of two or more different elements
Element
Substance that cannot be seperate D into simpler substances
Mixture
Matter that can be physically separated, combination of two or more pure substances
Uniform mixture
Homogenous mixture
Not uniform mixture
Heterogenous mixture
Graphite:
Pepper:
Sugar:
Soda:
Element
Hetero mix
Compound
Solution
Law of definite composition
A given compound always contains the same fixed ratio of elements
Law of multiple proportions
Elements can combine in different ratios to form different compounds
Solution
Homo mix
Particles don’t settle
No Tyndall effect
Extensive or intensive identify Boiling point: Volume: Mass: Density: Conductivity:
Intensive Extensive Extensive Intensive Intensive
Percent composition
Percentage by mass of each element in a compound
%comp.=
mass of element/total mass X100
If matter can’t be separated physically it is a
Pure substance
Ideal gas
No volume
No velocity when collide (elastic collisions)
Random straight motion
Real gas
Own volume attract each other
Gas behavior is most ideal at
Low pressures
High temps
Dividing numbers with sig figs,
Smallest number
Using density find volume of a certain grams
Divide the grams by the density
Calculating percent error
Difference/correct
Rutherfords experiment indicated that
Positive charges are concentrated in a very small core at the atoms center
When given electron configuration how do you find the element
Count superscripted to determine electrons
How to find valence electron
Biggest number in electron configuration
How to find unpaired electrons
Draw last sublevel
What have the same valence electrons
Down a group
If an atom gains electrons what happens to radius
Radius increases
Higher pressure means what for molecules
More molecules
At constant pressure the volume of a mole of any ideal gas varies
Directly with kelvin temperature
Not an assumption of matter made by kinetic molecular theory
When particles collide their total energy decreases
