Studied by 7 people
What is a fact?
an objective, verifiable observation (example: water boils at 100C)
What is a principle?
a statement based on repeated experimental observation that describes an aspect of the world (example: greenhouse effect)
What is a law?
a broad concept or principle that describes patterns in nature and are often accepted as facts (example: Newton’s laws of motion)
What is a theory?
an explanation of an observed phenomenon and organizes facts and research from scientists to explain why but never becomes a fact or law (example: evolutionary theory)
What is science based on?
experimentation
What is the best glassware for measuring?
graduated cylinders
What is the curved line on a graduated cylinder called?
meniscus
What is the best glassware for performing small chemical reactions?
test tubes
What are used for growing bacteria cultures?
Petri dishes
What are the steps to an investigative process sequence?
ask a question
conduct background research
construct a hypothesis
test the hypothesis in an experiment
analyze the data
draw conclusions and communicate them
What is an observation?
a description of something you can see, smell, tough, taste, or hear and is not an opinion (must be objective)
What is an inference?
a guess about an object or outcome based on your observations; you can make many inferences from a single observation
What can observations be?
either qualitative or quantitative
What is a qualitative observation?
describes qualities
What is a quantitative observation?
uses numbers to measure something
What is precise data?
how close your measurements are to each other (is this data consistent? Is the data specific?)
What is accurate data?
how close your measurement is to the correct/accepted value (is the data correct? Give the most accurate data)
What does conducting background research lead to?
defining the purpose/objective for the experiment
What is the overall goal of a scientific investigation?
to answer a question
What is the general path to defining a purpose?
our observations lead to questions, lead to research (what has already been found out about this question), leads to defining a purpose
What is a purpose/objective?
a statement that clearly shows what question you are trying to answer in your investigation
What is a hypothesis?
a testable prediction based on observations that describes a cause and effect relationship between variables
What is the format for a hypothesis?
“If (IV) then (DV) iv= independent variable= cause dv=dependent variable=effect
What is an independent variable?
what the experimenter will deliberately change or manipulate in the investigation; is usually on the x-axis of a graph; should be the only thing different between experimental groups
What is a dependent variable?
what changes in response to the independent variable; on the y-axis of a graph; usually represented by the data you collect in an investigation/what is measured
What should the materials include?
what you need to conduct the experiment; includes amounts, brands (if important), are as specific as possible, and are written as a bulleted list
What should the procedures include?
every step that was taken so that someone could replicate the experiment, starts with an action word, and is a numbered list
What is the experimental group(s)?
groups that are being tested
What are the control groups?
groups used for comparison with your experimental groups (the “normal” group)
What are constants?
the aspects of an experiment that are held constant/consistent to ensure that all aspects of trials are identical (minus the IV) and that any difference measured in the DV is caused only by the IV
What do results include?
the data collected during an investigation in an organized form, presented in an easy to read way, such as a graph
What do analyses include?
statements about what the data show, highlight any trends or patterns seen in the data and discuss any potential errors in the data
What does having as many repeated trials as possible do?
ensures the results aren’t by chance, eliminates any errors, and ensures the data is precise
How do you draw conclusions and communicate them?
make an explicit statement about whether your hypothesis was supported or rejected by your experimental data (may support or fail to support your prediction but data does not prove/disprove), describe any real world applications/uses for the information learned from the investigation
What is science?
leads to the advancement of knowledge, answers questions based on our observations
What is technology?
leads to the advancement of society, solves problems based on our needs, the application of scientific discoveries to meet human needs and goals through the development of products and processes
What is engineering?
applies scientific and mathematic principles to solve problems (science plus technology field)
What is problem identification?
clearly defines the problem or need
What is solution design?
brainstorm, research, sketch, and narrow down to the best design for product or process all within constraints such as: cost and time effectiveness, materials (availability, durability, environmentally conscience, etc). The perfect design is never possible but the benefits outweigh the risks
What is implementation?
build and test, continually making improvements
What is evaluation?
determine if you solved the problem and met all of the constraints of the project
What are the 4 steps to technological design?
problem identification
solution design
implementation
evaluation
What is matter?
anything that has mass and occupies space and is composed of atoms
What is an atom?
the smallest part of an element that still has the properties of that element
What are the 6 elements necessary for life?
C,H,O,N,P,S
What is a cell?
the most basic unit of life
What are atoms made of?
subatomic particles
Where are the subatomic particles located?
protons and neutrons in the nucleus and electrons in the electron cloud
Where is the majority of an atom’s mass?
in the positively charged nucleus
Where is the majority of an atom’s volume?
in the negatively charged electron cloud
What can we gather from the periodic table?
elements’ symbols, atomic number, average atomic mass, etc
What is an element’s atomic number?
the number of protons that can identify the element and equals the number of electrons in a neutral atom
What is average atomic mass?
the sum of protons and neutrons in the most common isotope of the element
What is an isotope?
2 or more forms of the same element, with different numbers of neutrons (written as the element’s name, mass number- protons + neutrons, or as the symbol)
What is the electron cloud divided into and how many electrons do they hold?
energy levels, or shells. The innermost level holds up to 2 electrons and the rest hold up the 8
What are the electrons in the outermost energy level called?
valence electrons
What does the group (columns) number of a periodic table tell?
how many valence electrons an atom has
What does the period (row) number of a periodic table tell?
how many energy levels an atom has
What do all atoms want/ what does that mean?
they want to be stable so they need full energy levels of electrons
How do atoms get full levels of electrons?
they form chemical bonds to make compounds
What is a compound?
2 or more atoms of different elements bonded together
What is a molecule?
2 or more atoms covalently bonded together
How do covalent bonds occur?
when nonmetallic atoms share electrons
How do ionic bonds occur?
when electrons are transferred from a metal to a nonmetal
What forms a cation?
when an atom loses an electron and becomes more positively charged
What forms an anion?
when an atom gains an electron and becomes more negatively charged
What is water?
a molecule made of 2 atoms of hydrogen covalently bonded to 1 atom of oxygen, is critical for all of life’s processes and has special properties because its polar
What is a polar molecule?
unequal distribution of charges, one side is more positive, one is more negative and dissolves in water
What is a non polar molecule?
no separation of charge, no positive or negative poles are formed, doesn’t dissolve in water
Why can a water molecule be attracted to each other?
it has hydrogen bonding
What holds water molecules together internally?
stronger covalent bonds
What holds different water molecules together externally?
weaker hydrogen bonds
What are the 5 properties of water?
cohesion
adhesion
high specific heat
less dense as a solid
water is a terrific solvent
What is cohesion?
the attraction between molecules of the same substance; tendency of molecules of the same kind to stick together, causes high surface tension
What is surface tension?
measure of how difficult it is to stretch or break the surface of a liquid/resist an external force
What is adhesion?
the type of attraction that happens between 2 different molecules, forms stronger bonds than cohesion
What is high specific heat?
the temperature of water does not change easily; it has to absorb more heat energy to increase overall temperature compared to other compounds
What are some of the benefits of water having a high specific heat?
it helps regulate cell temperatures in organisms, allows life to live in water, buffers large fluctuations in temperature which keeps Earth’s climate moderate
What does it mean if water is less dense as a solid?
ice is less dense than liquid water so it floats in liquid water (this means life can exist under frozen surfaces of lakes/polar seas)
What is a solution?
uniform mixture of two or more substances
What is a solute?
what gets dissolved
What is a solvent?
what does the dissolving
Why is water good at dissolving things?
it is polar
Why is water considered the universal solvent?
it dissolves more substances than any other liquid
What does hydrophilic mean?
has an affinity for water (water “loving”), usually dissolves easily in water (example: salt)
What does hydrophobic mean?
does not have an affinity for water (water “fearing”), does not dissolve in water (example: oil)
What are macromolecules?
large organic molecules that make up all living things
What are the 4 macromolecules?
carbohydrates, lipids, proteins, and nucleic acids
What are macromolecules made of structurally?
polymers made of monomers
What are monomers?
small basic sub units
What are polymers?
larger more complex structures made of monomers
What is a dehydration reaction?
builds a polymer by linking monomers (does this by removing a water molecule: both monomers have a hydroxy group, pull out OH from one and H from another to form water, oxygen to bond 2 monomers to form polymer)
What is hydrolysis?
breaks big polymers into smaller monomers by adding water, which breaks bonds
What is lysis?
breaking apart water
What is the main function of a carbohydrate?
short term energy storage
What are other uses of a carbohydrate?
structure, transport, signaling
What are carbohydrates found in?
sugars and starches
What are carbohydrates composed of?
C,H,O
What is the monomer of a carbohydrate?
monosaccharides (single sugar molecules)
What is the polymer of a carbohydrate?
polysaccharides (larger sugar molecules)
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