chapter 1 Flashcards
what is chemistry
the study of matter and the changes it undergoes with the atom being its basic functional unit it is also the study of 2 comp, structure, properties, and reaction of matter.
what is matter
anything that occupies space and has mass
what 3 types is it classified into
element, compound, and molecule
what is an element
the simplest type of matter that is composed of 1 type of atom
what is a compound
matter composed of 2 or more diff elements that are chemically bonded together
what is a mixture
matter composed of elements and or compounds that are physically mixed together
what is a physical change
changes in the physical state of a substance without a change in composition ( what its made of)
examples of physical changes include
dissolving of a solute and mixing a substance
what are examples of dissolving a solute
chopping , cutting, tearing, breaking a material
what is an example of mixing a substance
crushing it
which change is a physical change
a. wood burning
b. iron rusting
c. dynamite exploding
d. dissolving sugar in water
d. dissolving sugar
which of the following is a chemical change
a. melting wax
b. cooking an egg
c. condensing water vapor
d. carving a piece of wood
b. cooking an egg
ie if were burning cooking or baking were changing the chemical bonds
pure substance
is in the classification of matter: single composition
is an element separable into simpler substance
NO examples O2
Is a compound separatable into simpler substances
yes examples H20 can be separated
mixtures
are a variable composition in the classification of matter
is heterogenous mixtures in a uniform comp
No it is not it is comp of diff sub like oil and water
is homogenous mixs in a uniform comp
yes it is for example air because it is comp of alot of diff things but it all looks the same to us
consider the following subs
1. Gatorade
2. crystalline sugar
3. lead wire
4. salsa
when it comes to classification of matter thing of it in terms of comp then we can separate into categories
2 and 3 1 is a homogenous
which of the following is true
a. compounds can only be broken by chemical means
b. gasoline is a pure substance
c. only elements are pure substances.
d. milk is a homogenous
e. concrete is homogenous
a. compounds can only be broken by chemical means
choose the homogenous mix
1. soda
2. smog
3. trail mix
4. blood
5. air
air
choose the homogenous mix
a. chicken noodle soup
b. coffee
c. sand
d. fruit salad
e. seawater
coffee
classify each of the following as an element, compound , or mixture
a. ammonia NH3
b. gold bar
c. orange juice
d.wine
e.saline solution
q. compound
b. element
c.mixture
d.mixture
e. mixture
basically what is a chemical change
it changes the identity of your substance
examples of chemical changes
rusting of metal
burning of material
metabolism of food
chemical reactions
color change
odor change
which of the following is a physical change
a. milk sours when left out of the fridge
b. tums ( has CaCO3) neutralizes stomach acid
c. sugar caramelizing when heated on a skillet
d. tearing a piece if paper
d. tearing a piece of paper
what is a reversible change
a change that can be reversed to restore the original structure of a given compound
examples of reversible changes include
phase changes, dissolving of compounds in a liquid,and physical changes most common ex of a phase change is CO2 (s) to CO2 (g)
bond forming phase change is
molecules within our substance are coming closer together and forming connections
gas to liquid is called
condensation
liquid to solid is called
freezing
gas to solid is called
deposition because your depositing a solid
bond breaking is
can break bonds going through the diff phases of matter
solid to liquid is called
melting or fusion
liquid to gas is called
vaporization
solid to gas
is called sublimation
irreversible change is
something that is permanent cannot be undone to restore original structure
irreversible changes deal with
chemical changes that change the identity of our original material
ex - N2 (g) + 3 H2 (g) to 2NH3 (g)
the result is chemically bonded it is an irreversible process
are the following processes reversible (physical change) or irreversible (chemical change)?
a. dissolving sugar in water
b. adding lemon juice to cabbage juice (causes the color to transition from purple to deep red)
c. adding citrus to baking powder
d. mixing oil and water
a. reversible
b. irreversible
c. irreversible
d. reversible
which of the following represents a reversible change?
a. melting a chocolate bar then re solidifying it in the freezer
b. changing water vapor into oxygen and hydrogen gas
c. turning a potato into french fries
d. baking a cake from a recipe
a. melting a chocolate bar then freezing it
a chemical property is
a property of matter that is observed during a chemical reaction. the matter us changed into a new substance after the reaction.
ex - 2 CH3OH (g) + 3O2 (g) to 2CO2 (g) + 4H2O (g)
reactants are
are before the arrow 2 CH3OH (g) + 3O2 (g) arrow 2CO2 (g) + 4H2O (g)
products are
after the arrow are products 2 CH3OH (g) + 3O2 (g) arrow 2CO2 (g) + 4H2O (g)
chemical properties
are in some way related to chemical reactions (changes)
common types of chemical properties
flammability, toxicity, corrosion, reactivity, radioactivity, solubility ( how are solid compound the liquid and solid how they interact with one another) if its soluble its broken down by liquid
which of the following is not a chemical property for an unknown element ?
a. it has a yellow orange color
b. it is very soluble in an acid solution
c. it is radioactive
d. it experiences rusting when exposed to pure oxygen gases
e. it has a high reactivity with acids
a.
which of the following represents a chemical property of hydrogen gas?
a. it exists as a gas at room temperature
b. it is less dense than air
c. it reacts explosively with oxygen gas
d. it is a colorless gas
e. it is a tasteless molecule
c. it reacts explosively with oxygen gas
what is a substance
just another word for matter
what is a chemical
a substance that always has the same comp and properties wherever it is found. ex - toothpaste is an ex of many chemicals
what is structure
how it is put together
what are properties
what characteristics it has
what are reactions
how it behaves with other substances
which of the following does not contain chemicals
a. sunlight
b. fruit
c. milk
d. breakfast cereal
a. is correct because its energy given off by sun so has no chemicals
what is scientific method
a set of general principle’s that helps to describe how a scientist thinks
how is the scientific method organized
observations, hypothesis, expieriments, conclusion/theory
how are observations made
by asking questions about nature about what you observe if an observation seems to be always true can be stated as a law but we cannot always see why this law happens
what is a hypothesis
a possible explanation for observations
what are experiments
to determine if hypothesis is true or not to see correlation between the hypothesis and observation can confirm it but if not can be modified or discarded
what is a conclusion/theory
when results of an experiment is analyzed a conclusion tells us whether they are true or false
identify the following as a observation, hypothesis, experiment, or conclusion,
a. during an assessment nurse writes a patients pulse as 30 bpm
b. repeated studies show that lowering sodium in the diet leads to decrease in bp
c. a nurse thinks an incision from a surgery that is red and swollen is infected
a. observation
b. conclusion
c. hypothesis
place value ex
ones place value is first to the left of decimal tens is 2nd hundreds is 3rd and thousands is 4th
place value tenths ex
tenths is 1st to right of decimal hundredths is 2nd to right and thousandths is 3rd to right
what is place value for each digit 0.925
9 is in tenths 2 is in hundredths and 5 is in thousandths
how to calc percentage
divide the parts by the total (whole) and multiply by 100%
ex - 325 mg of asprin / 545 mg tablet X 100 = 59.6 %of asprin in tablet
why is the value of 100% used in the calculation of percentage?
because it represents parts of an item in 100 of those items.
ex - 5% of red balls 5/100
solving equations 2x+8=14
place all like terms on one side, isolate variable you need to solve for, then check answer
what is scientific notation
used to turn small or large numbers into manage numbers
what is a coefficient of 6.88 x 10^-12
beginning part of the value that is greater than 1 and less than 10 in this case it’s 6.88
what is the base of 6.88 x 10^-12
the portions that is always 10
what is the exponent of 6.88 x 10^-12
the number of decimals that were moved in order to create the scientific notation value -12 must be a whole number integer
which of the following is correct
a.1.25 x 10 ^-1/4
b.0.00320 x 10 ^-9
c.5.220 x 10 ^3
d.7.3000 x 2^7
c. 5.220 x 10 ^3
what is standard notation
normal way of writing number
what does a positive exponent tell you
it means the coefficient number is larger and the decimal point is moved to the right ex - 7.17 x 10^5 = 717,000
what does a negative exponent tell you
it means the coefficient number is smaller and the decimal is moved to the left ex - 3.25 x 10 ^-7 = .000000325
convert the following values into standard notation
a.1.25 x 10^-4
b.3.20 x 10 ^-9
c.1.6100x 10 ^4
a. .000125
b. .00000000320
c. 16,100
to convert from standard notation to scientific notation the number must be
between 1 and 10
increasing the coefficient value makes the exponent value ex - 0.0000145
decrease ex - answer 1.45 x 10 ^-5
decreasing the coefficient value makes the exponent value ex -
increase answer ex - 1.01325000 x 10^8
Convert the following standard notation values into scientific notation.
a. 377,000
b. 0.000101
c. 707.82
a. 3.77000 x 10^5
b. 1.01 x 10^-4
c. 7.0782 x 10^2
