TX PACT 4-8 CORE (790) Exam with complete solution
1 view 0 purchase
Course
TX PACT
Institution
TX PACT
TX PACT 4-8 CORE (790) Exam with complete solution
How many SFs in 0.?
8
SFs: Addition and Subtraction Rules
answer has the same # decimal places as numeral w/the smallest # of decimal places.
EX: 1063.02 + 12.5 = 1075.5
SFs: Multiplication/Division Rules
answer has the same # of SFs as nu...
tx pact 4 8 core 790 exam with complete solution how many sfs in 0010025600 8 sfs addition and subtraction rules answer has the same decimal places as numeral wthe smallest of decimal places
Written for
TX PACT
All documents for this subject (71)
Seller
Follow
LECTMAGGY
Reviews received
Content preview
TX PACT 4-8 CORE (790) Exam with complete solution
How many SFs in 0.010025600?
8
SFs: Addition and Subtraction Rules
answer has the same # decimal places as numeral w/the smallest # of decimal places.
EX: 1063.02 + 12.5 = 1075.5
SFs: Multiplication/Division Rules
answer has the same # of SFs as numeral with smallest # of SFs.
EX: 1063.02 x 12.5 = 13287.75 => 1.33 x 10^4
Define: Hypothesis, Theory, and Scientific Law
Hypothesis: testable prediction based on observations (educated guess)
Theory: proposed explanation, based on evidence, that may or may not be testable.
(educated explanation on why something happens)
Scientific Law: proven and documented description of observations surrounding
phenomena (states what will happen not why)
*theories do not become laws
independent variable
The experimental factor that is manipulated by the scientist; the variable whose effect is
being studied. (usually on x-axis)
dependent variable
The measurable factor; the variable that may change in response to (or depend on)
manipulations of the independent variable.
Precision
a measure of how close a series of measurements are to one another
Accuracy
how close a measurement is to the true value
Negative feedback
A type of regulation that responds to a change in conditions by initiating responses that
will counteract the change or correct the system back to original state. Maintains a
steady state (homeostasis).
EX: body temperature
Positive feedback
A type of regulation that responds to a change in conditions by initiating responses that
will amplify the change. Takes organism away from a steady state.
EX: Global warming or contractions
Matter
Anything that has mass and takes up space (made up of atoms)
Ground state of atoms
lowest energy, most stable electron configuration
Neutrons
neutral charge; mass # - atomic # (protons)
Quantum Model
current atomic model in which e- move in waves around nucleus (w/ uncertain positions
in an e- cloud)
,Molecules vs. Compounds
Molecules: Groups of two or more atoms held together by chemical bonds
Ex: O2 & consist of compounds too
Compounds: 2 or more DIFF. elements held by ionic or molecular bonds
Ex: H2O, NaCl, etc..
Isotopes
atoms w/ same # of protons, but diff. # of neutrons
Radioactivity
The spontaneous nuclear emission of radiation by an unstable atomic nucleus, which
changes # of protons (identity of element)
Alpha Decay
Radioactive decay in which an atom emits an alpha particle (w/ 2P and 2N). This
decreases the atomic # by 2 and the mass number by 4.
emission of helium-4 nucleus
Beta Decay
radioactive decay in which neutron changes into proton by emitting an e- and neutrino.
This increases atomic # by 1 and mass stays the same.
emission of an electron or a positron
Gamma Decay
radioactive decay by emission of a gamma ray; atomic # and mass # do not change.
carbon dating
uses half life to approximate age of fossils.
solute
the substance that is dissolved in solvent
"pUT the solUTe in the solvent"
density
mass/volume
Kinetic Molecular Theory of Matter
all matter is constantly in motion
- KE and speed increases as temp. increases
Wind turbine energy transformation
kinetic (wind moves motor) to mechanical (generator)
strongest to weakest bonds
covalent, ionic, hydrogen
types of bonds
- covalent: e- are shared b/t 2 atoms (usually NM)
- ionic: oppositely charged ion attraction - one atom loses e-, other accepts [one M (+),
one NM (-)]
, - metallic: 2 metal atoms
- hydrogen: weak bonds, easily breakable
states of matter
solid: rigid, fixed shape & volume
liquid: fixed volume
gas: compressible
during a phase change, temp. is constant until change is complete and matter is
conserved
Combination Rxn
A+B-->AB
Decomposition Rxn
AB --> A + B
Single Replacement Rxn
One element/molecule replaces another
A + BC --> B + AC
Double Replacement Rxn
AB + CD --> AD + CB
Combustion Rxn
C reacts with O2, burns, and produces CO2 and H2O in the process.
Redox Rxn
transfer of electrons that changes charge (oxidation #) of atom in the reaction
Oxidation
OIL = losing e-
0 --> 1+ b/c lost an e- to make + charge
Reduction
RIG = gaining e-
1+ --> 0 b/c gained an e- to make neutral charge
Energy
ability to create heat or do work; always conserved
Thermal Energy
The total internal energy of all of the particles motion in a substance -- transfers heat
Heat Energy
transfer of thermal energy - energy transferred from hot to cold
Laws of Thermodynamics
- Zeroth: 2 bodies are in thermal equil. w/ 3rd body, then they are all in thermal equil.
(have the same temp.)
- 1st: Internal Energy (U) = Heat (Q) - Work
Work done by system = +W
Work done on system = -W
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LECTMAGGY. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.98. You're not tied to anything after your purchase.
