Chem ch. 1

• Promote understanding of how the univerese and its parts function
• IE: astronomy; biology; chemistry; physics

• Makes uses of the results of pure sciences
• IE: agriculture; engineering; medicine

• Study of non-living material
• -composition materials and changes materials undergo
• -energy changes that accompany chemical changes
• -discover and develop new material from existing ones

series of activities involving observations and experimentation and culminating of theories to explain and predict natural phenomena

• Observations (what you see / collection of data)
• Question and hypothesis (hypothesis: tentative answer to the question / explanation for the properties or behavior of matter that accounts for a set of observations must be testable)
• Experimentation: (Date, Title, aim/purpose, list of equipment, procedure, data analysis, and conclusion)

Describes how nature operates under a specific set of conditions

Explains why observations, hypotheses, or laws apply under many different circumstances

factor varied by you

factor that will change as a result of a change in the independent variable

• serves as a standard for comparison
• exposed to smae conditions as teh experiment except for the variables to be tested

all the factors that the experimenter attempts to keep unchanged in the course of the experiment

replicate groups subjected to the same conditions in an experiment

anything that occupies space nad has mass

• does not occupy space / have a mass
• eg: sunlight/heat

• pure substances that contains atoms of one type
• cannot be broken down into simpler substances even by a chemical reaction

substance composed of 2 or more elements combined in defined portions IE: water

• 90 of the 144 elements / appear on L side of periodic table
• properties:
• -solid at room temp (except mercury)
• -good conductor of heat/electricity
• -lustrous on fresh surfaces
• -malleable & ductile

• 17 elements / Appear on the R side of periodic table
• Room temp: 11 gases / 5 solid / 1 liquid
• poor conductors of heat & electricity

Seven elements are metalloids. Their properties are between those of metals and nonmetals. Metalloids are semiconductors and are important to the electronics industry. (a) Boron and (b) silicon are examples of metalloids

• 2 or more substances that are physically mixed, not chemically combined
• 2 or more substances in different proportions
• substances that can be serperated by physical methods

• composition is uniform throughout
• different parts in mixture are not visible

• composition of substances is not uniform
• composition varies from one part of the mixture to another
• different parts of mixture are vissible

• filtration
• evaporation to dryness
• simple distillation
• fractional distillation
• magnetism
• precipitation

• decantatin
• winnowing
• handpicking

• fixed shape that is not related to the shape of the container holding it
• low compressibility (particles are tightly packed)

• no fixed shape
• fills only the portion of container it occupies
• can be slighlty compressed ( particles have little free space)

• no fixed shape
• expands to fill its entire container
• changes volume when compressed

dissoled in water

• measured withoug changing substance
• physical state / color / odor / density / boiling point

• describes substance's reactivity
• flammability / corrosiveness

• depends on the amount of matter present
• mass / volume

• does not depend on the amount of matter present
• density / color / temperature

=mass/volume

• T_K=T_C +273.15
• T_F = 1.8(T_C)+32

• process in which one or more substances are converted into one or more new substances
• bubbling / permanent color change / sudden change in temperature

process that changes the physical properties of a substance without changing its chemical composition

• the extent of the agreement between repeated measurements of its value.
• If repeated measurements are close in value, then the number is precise, but not necessarily accurate

• the difference between the value of a measured number and its expected or correct value.
• The number is accurate if it is close to its true value (much like hitting a bulls-eye on a dart board).

• A possible approach to problem solving involves 4 steps:
• 1 .Decide what the problem is asking for.
• 2.Decide what relationships exist between the information given in the problem and the desired quantity.
• 3.Set up the problem logically, using the relationships decided upon in step 2.
• 4.Check the answer to make sure it makes sense, both in magnitude and units.

capacity to do work or transfer heat

the energy due to motion

energy possessed by an object becasue of its position

• 4.184J = 1 cal
• calorie is the amount of energy required to raise 1g of water by 1^o C
• 1 Cal = 1000 cal

process that releases heat energy

process that absorbs energy