General Chemistry - Chapter 1 Flashcards
Atoms
Smallest fundamental building block of matter that’s all around us. Ex: Water has 3 atoms… 2 Hydrogen, 1 Oxygen
What is Chemistry?
The studying of matter by studying atoms & molecules. (Study the MACRO by studying the MICRO)
What are the 4 steps of Scientific Method? (in order)
Observation, hypotheses, experimentation, laws & theories
(It CANNOT be scientific method without proving or disproving the hypothesis)
Scientific Law vs Scientific Theory.
Law takes past observations used to predict future ones. (WHAT Nature does)
A theory focuses on how and WHY a phenomena happened. It takes data and forms a statement/idea. (Can be retested for)
What is Matter?
Anything that takes up space in the form of solid, liquid, or gas.
Atoms & molecule structure in Solids
The atoms or molecules do not move around, therefore solids don’t have motion.
Atoms & molecule structure in Liquids
The atoms or molecules move freely, therefore liquids have motion.
Atoms & molecule structure in Gas
The atoms or molecules move freely in a changing volume, with a shape that is not constant, therefore gas moves sporadically and freely.
What is Pure Matter?
Substance made up of one element or compound. (Bonded together)
What is a Pure Element?
One kind of atom. Ex: Oxygen O2
What is a Pure Compound?
Made of more than one kind of atom. Ex: Water H2O
What is a Mixture?
2 or more kinds of elements or compounds mixed together. Ex: Saltwater
SEPARATING MIXTURES: Distillation
Liquid is boiled, vapor enters a cooling-chamber, condenses to a liquid, called distillate, and is collected as a PURE liquid.
SEPARATING MIXTURES: Filtration
Mixture is poured in a funnel — liquid is separated from solid.
What is a Physical Change?
Changing appearance or state of substance, but not composition. Ex: Liquid Water to Ice
What is a Chemical Change?
Changes content inside of substance. Ex: A nail rusting - changes from iron to iron oxide.
What is Energy?
The capacity/ability to do work.
What is Work?
Applying force through a specific distance.
ENERGY: Kinetic
Associated with motion.
ENERGY: Potential
Associated with position or composition. Ex: A rock at the top of a cliff’s edge or a burger you’re about to eat.
ENERGY: Thermal
Associated with Temperature; A KIND of KINETIC energy because more heat equals more motion of atoms.
What is the Law of Conservation?
Energy is not created nor destroyed. Always conserved in a physical or chemical change.
What are units?
Qualities used to specify measurements/quantities. Ex: 5 CENTIMETERS
STANDARD UNITS: Length
Meter: m (unit: symbol)
STANDARD UNITS: Mass
Kilogram: kg (unit: symbol)
STANDARD UNITS: Time
Second: s (unit: symbol)
STANDARD UNITS: Temperature
Kelvin: K (unit: symbol)
STANDARD UNITS: Amount of substance
Mole: mol (unit: symbol)
STANDARD UNITS: Electric Current
Ampere: A (unit: symbol)
STANDARD UNITS: Luminous intensity
Candela: cd (unit: symbol)
Mass vs Weight
Mass is the amount of matter in an object, weight is the force or gravity on an object. Weight can change depending on gravitational pull, while mass always stays the same.
Explain the Kelvin Scale (absolute scale)
Assigns 0 K (ABSOLUTE ZERO) to the coldest temperature possible. (Absolute zero = -273.15°C or -459°F)
What’s an Intensive Property?
Property thats independent of the amount of substance. Ex: Density
What’s an Extensive Property?
Property thats dependent of the amount of substance.
Ex: Mass
Density
Mass of substance and how much volume/space it takes (D = m/v)
Sig Figs: moving from left to right
negative (#^-#) Ex: 0.000013 x 10
1.3 x 10^-5
Sig Figs: moving from right to left
positive (#^#) Ex: 149,600,000
1.496 x 10^8
Sig Fig Examples
01010 = 3 SF
0.003080= 4 SF
01010.0 = 5 SF
0.01010 = 4 SF
.0209 = 3 SF
How to round Addition & Subtraction?
Count lowest decimal places
How to round Division & Multiplication?
Count lowest sig figs
Precision vs Accuracy
Accuracy is how close a measured value is to the actual value, while precision refers how close a series of measurements are towards one another. Ex: Fine tuning is precision, weighing a bear and comparing that weight to the average weight is accuracy. (OR THINK OF IT ON A GRAPH)
