Learning Objectives 1 Flashcards
Explain/define physical change
Physical change: relates to the physical characteristics of matter such as color, shape, melting pt, boiling pt, density, etc.
- A physical change can be observed or performed w/o changing the composition or chemical properties.
Ex.) boiling water, tearing a piece of paper, dissolving salt in water.
Explain/define chemical change
A chemical change: refers to the composition of matter. Therefore, undergoing a chemical change changes the composition to make a new product that is chemically different from the original.
What are the different states of matter?
Solid, liquid, and gas
List the characteristics of a solid
- Has a fixed shape
List the characteristics of a liquid
- Has a varying shape. Takes the shape of its container
- Has a flat upper surface
- molecules are positioned close together but are random
List the characteristics of a gas
- Has no shape.
- molecules are positioned randomly far from each other Takes the shape of the container
- has the largest kinetic energy, therefore have the least attraction between them.
Which of the following are physical properties?
A. Melting pt. B. Temperature C. Boiling pt D. Density E. flammability
A, B, C, & D
Which of the following are Chemical properties?
A. Toxicity B. Volume C. Acidity D. Heat of combustion E. Color
A, C, & D
Define atom
The basic unit of matter. Contains protons, neutrons, and electrons
Define element
A specific species of atoms. Has a certain number of protons
Define molecule
2 or more atoms of an element (identical)
* often interchanged with the word compound
Define compound
2 or more different elements bonded together
What is molecular Oxygen?
O2
What is the scientific method process?
- Observation- What we can see
- Hypothesis- What we are testing for and has not been proven yet
- Procedure- the steps taken to test the hypothesis, if true or not
- Results- based on the procedure
- Discussion- what do these results say or not say
- Conclusion- what do these results mean with respect to the hypothesis? what can be concluded with the given info
Volume units
m^3
cm^3
Liters
mass units
grams, kilograms, etc
length (area)
meter^2, cm^2, etc
temperature
Celcius (C), Kelvin (K), and Fahrenheit (F)
Compare mass and weight
Mass: mass is a property of matter.
- the mass of an object is the same everywhere
- can never be zero
- scalar quantity
- mass= Kg or g
Weight: weight depends on the effect of gravity.
- it varies depending on the location
- can be zero, if no gravity acts on an object
- vector quanity
- weight = (mass)(gravity) = N (newtons)
Compare heat and temperature
Heat: heat is a form of energy (thermal energy)
- is exchangeable
- cannot be measured unless flowing from one “body” to another
- not a property of matter
- quantified in joules
Temperature: temp. is the degree of hotness or coldness of a “body”, not energy
- not exchangeable
- can be measured
- the avg. K.E of molecules in a substance
- Measured in C, Kelvin, or F
Compare intensive and extensive
Intensive: intensive properties do not vary depending on the amount of material
Ex.) melting pt, boiling pt, viscosity, temperature
Extensive: extensive properties vary depending on how much material is present
Ex.) Volume, mass
Accuracy vs. Precision
Accuracy: result is IDENTICAL to the accepted value
Precision: result is CLOSE BUT NOT EXACTLY the accepted value. results are also close to each other in range
systematic error vs. random
systematic error: instrument/system is responsible for the error. the error is also reoccurring
random: a combination of instrument and human error or one or the other, but the error is infrequent.
absolute percent error equation
% error = |theoretical value - experimental value / theoretical value| x 100
theoretical = measured…actual…true
