What you must know for the Science Starr
1.
Scientific Method: Observation
Question
Research
Hypothesis
Test
Hypothesis through Experiment or Repeated observations ( One independent aka experimental)
variable leading to a result (aka dependent variable)
repeated TRIALS
conclusions
a. Variables – independent, dependent, confounding
b. Constants – things you keep the same to prevent confounding variables
c. Trials – repetition of tests or experiments
d. Use of models to “see” things we can’t see in real life.
e. The importance of evaluation of experimental design and critique of design- create
experiments to test a hypothesis
f. Inferences - draw inferences from information provided
g. Importance of Measurement and use of the correct tools to measure what we observe.
h. Safety practices
2. Measurement tools and units: Grams - mass (balance) weight – the pull of gravity on a mass
(spring scale), Liters - Volume (graduated containers – measurement practices – level, no
bubbles, bottom of meniscus); Meters – distance; Time. Remember the importance of always
finding zero, which means that you must always calibrate your tool before you use it.
3. Physics: physics is the study of how things in the PHYSICAL world work. It involves movement,
creation, and change.
a. Force (push or pull: including gravity, friction)
b. Energy –ability to do work
c. Effort
d. Work – force over distance
e. Newton’s three laws of motion: 1.object in motion stays in motion; 2.force = mass X
acceleration; 3. every action has an equal and opposite reaction.
f. Simple machines: inclined plane family: inclined plane, wedge, screw and the lever
family – levers, wheel and pulley. Trading effort, for distance. You must move the
object farther but it requires less effort to move.
4. Chemistry:
a. Matter – anything that takes up space/has mass
b. Rule of conservation of matter and energy =matter cannot be created or destroyed.
This means the total amount of matter in a system can’t change. 40g of a solid
dissolved in 100g of a liquid will have a mass of 140g not more or less. If you add 4ml of
something to 6ml of something else, the new volume will be 10ml not more or less.
c. States of matter: common – liquid, solid, gas- solids have a definite shape and a definite
volume, liquids have no definite shape-they take the shape of their container-but they
have a definite volume-gases have no definite shape and no definite volume there
volume and shape depend on the container they are in. They expand to fill their
container and take the container shape; Also common, but not tested on the Staar is
Plasma – superheated gas; [others, also not tested: BCE and Fermionic condensate –
these are man-made and exist only in the laboratory at near zero degrees Kelvin
(absolute zero.)]
b
d. Matter is classified based on physical properties
i. State in which they exist at room temperature (gas, liquid, solid) density
conductivity (heat and electricity), magnetism, , solubility in specific solvents,
melting point/freezing point and boiling point, malleability, etc.
1. Matter exists in a particular state at room temperature. Some things are
liquid, some are gas, and some are solid. This is one of the main
characteristics that is used to categorize matter. Mercury for example is
a liquid at room temperature but is a metal just like iron and is denser
than most elements.
ii. Mass: how much of matter is contained in an object. Objects with more mass
are harder to move and harder to stop. Think-real training vs. model train
1. Density-how tightly packed matter is. Two objects of the same volume
may have different mass and this means they have different density.
Things with lower density float on things with higher density whether
they are liquid, solid, or gas.
2.
Each type of matter has a different melting and boiling point.
You must know that water melts at 0°C/32°F and boils at 100°C/212°F.
Remember that the melting and freezing point, and the boiling and
liquefaction points are the same. Water melts and freezes at 32°F/0°C
and it boils or liquefies at 212°F/100°C. Whether it is melting or
freezing, boiling or liquefying, depends on which way the temperature is
going, up or down
iii.What matter is made of:
1. Elements-these are the basic building blocks of everything in the
universe. These work like a Lego blocks. Each is a certain type of matter
but each can join with other elements to create compounds which have
none of the properties of either of the elements that you started with.
Remember chlorine mixed with sodium creates salt.
2. Atoms-the smallest piece of an element that still has all the
characteristics of that element-make it any smaller or bigger and you
create a different element.
3. Compounds-when two or more elements combine to create something
new, they are called compounds. Water, salt, sugar, petroleum and DNA
are all examples of compounds.
e. MIXTURES AND SOLUTIONS
i. Chemical Changes-When matter is mixed, sometimes there is a reaction that
results in the original matter chemically changing resulting in the creation of a
new type of matter. These "chemical" changes result in the creation or removal
of heat. If there is a chemical change the mixture will heat up or cool down. It
may also release gas, change color, or change its physical and chemical
properties entirely. By comparison "physical changes" do nothing to the
properties of the material that you started with. Think of the difference
between burning a piece of paper and cutting it. Burning is chemical change,
cutting his physical change. Don't be fooled, melting, freezing, boiling, or
liquefying (changing state) are all physical changes and not chemical.
ii.
Physical Changes: When there is no chemical change in a mixture of
materials we call it a mixture. Duh. There are two types of mixtures,
homogenous and heterogenous. Remember the difference. -"hetero" means
different and "Homo" means same. Add these two "genus" which means type.
Think about the difference between salad and tea.
1. Heterogenous Mixtures -these mixtures can be changed by a simple
physical means. Remember iron filings, paperclips or other iron when
mixed with sand or other non-iron - separate with magnet. Salad or
similar mixture-separate with tweezers. Sand and gravel-separated
with strainer or sieve. Filtering-common means of separating
2. Homogenous Mixtures-cannot be easily separated by physical means
Most homogenous mixtures that they test on the Staar fall into a
category called solutions. Solutions are the best mixed mixtures with
particles so small you can’t see them. A solution is created when one
material [of a smaller amount] called a solute is placed in an other
material called a solvent [usually of a much larger volume.] A solvent
causes the particles of the solute to separate to an molecular level. This
means that you cannot see the individual particles of solute in the
solvent. Examples: lemon juice in water. Salt in water. Coffee. Tea.
Sugar in water. In each of these cases the solvent (water) is a liquid.
There are homogenous mixtures made of gases, for example the air we
breathe, and steel which is a mixture of iron and carbon.
5. ENERGY - you must understand the difference between forms of energy and sources of energy
and understand the difference between POTENTIAL and KINETIC
a. Forms of energy: mechanical (anything that is moving); electrical caused by the
movement of electrons through a conductor; electromagnetic spectrum-also known as
light; thermal-also known as heat; nuclear-which is caused by change in the nucleus of
an atom; sound; and chemical-which results from chemical reactions. Remember that
any form of energy can be changed into any other form of energy.
b. Sources of energy; solar-the sun's light, hydroelectric-the movement of water,
geothermal-the heat of the earth, biomass-energy from the bodies of present day
plants and animals, fossil fuels (petroleum/oil, natural gas, coal)-energy stored in the
remains of ancient plants and animals,
nuclear-released in the creation or
destruction of atomic nuclei. These are the
main ones. Know the advantages and
disadvantages of each, how we create each
type of energy, and where it comes from.
c. YOU MUST UNDERSTAND CIRCUITS.
d. You need to know what the following words
mean: radiant, insulator, conductor, and you
need to understand that certain things conduct heat and electricity better than other
things. A piece of metal conducts heat from one end to the other much better than a
piece of wood.
e. You also must know the terms renewable and nonrenewable resources.
f. Light: travels in a straight line (unless it's direction is changed by reflection, refraction,
or diffusion. It is extremely fast (186,000 mi./s) in fact it is the fastest thing in the
universe.
g. Light may be reflected, refracted, or diffused. Refraction is the bending of light: think
about a straw in a glass of water. Diffusion is not tested.
6. EARTH SCIENCE
a. The earth has layers: core (made of solid iron and nickel), mantle (inner and outer,
molten, magma) and crust (made of igneous, metamorphic, and sedimentary rocks and
soil which is made of ground-up rocks and the remains of plants and animals.)
b. The rock cycle-magma from the Earth's mantle comes to the surface and cools forming
igneous rocks; igneous rocks are destroyed by the processes of weathering and erosion
and deposited and cemented to form sedimentary rocks; sedimentary rocks are moved
into the heat of the mantle where heat and pressure change them into metamorphic
rocks. Metamorphic rocks often return to the Earth's mantle, melt, and start the process
over again.
c. The water cycle-collection, evaporation, condensation, precipitation, collection,
evaporation, etc. Understand that water may move above or underground but always
moves to the lowest points-the oceans.
d. Weathering: mechanical or physical (wind, moving water, moving ice, people and
animals); chemical-and acidic water; thermal (the expansion and contraction of rock
with the rise and fall of daily temperature)
e. Climate versus weather: weather is what is happening today, climate is the average
weather over a long period of time.
f. Clouds?-They rarely ask about them but if you want you can review the types of clouds,
something that you studied last year.
g. Plate tectonics-movement of continents, divergent, convergent, and transverse faults =
tension, compression, sheer
h. Landforms and water forms: Mountains, hills, valleys-glacial and River, sand dunes, etc.
i. Mountains-formed by tectonic plate collision causing one plate push under
another.
ii. Hills can be eroded valleys or created by
sand dunes that are changed to hills by
clients
iii. valleys-V-shaped = River; U-shaped =
glacier.
iv. Sand dunes and desert arches-wind
v. plateaus, mesas, hoodoos, and buttes-water and wind
vi. deltas-deposition of sediment at the mouth of a river (source = start-usually in
the mountains; mouth = end-in a larger River, Lake, Gulf, bay or ocean.
vii.
viii.
ix.
x.
i. Soil-soil is a natural resource that is
created from rock that has been
ground down into smaller and
smaller pieces and organic material,
which comes from the remains of
plants and animals. The parts of soil
are categorized as either inorganic
or organic. The inorganic part comes from rock and is
further categorized by the size of the pieces of rock. Very
were large rocks or boulders, which are chunks of the
earth's crust. Smaller rocks are called rocks. When rocks get
broken down into pieces that are even smaller we call it
gravel. The next smallest particle is called Sand. Then comes
silt, and finally the smallest rock particles are called Clay. These all combine with organic
material (stuff that was once alive) to create soil.
j. Soil profile: soil builds layer upon layer. Deeper layers are older layers. A fossil found in a
lower layer is older than one found in a higher layer. Don't forget sometimes layers get
shifted. Don't let that fool you. A soil profile is a cross-section of soil (take a flat shovel
and dig a trench) where you can see the layers. Here is an example:
k. Caves are created when acidic water percolates into limestone and eats it away leaving
hollow areas which we call caves. Water also creates stalagmites and stalactites.
Stalagmites and stalactites come together to form columns.
7. SPACE SCIENCE
a. You must know the planets
b. You must understand what gravity is and how it, along
with centrifugal force, controls the movement of
planets.
c. The earth rotates on its axis; this causes the sun to rise
in the East and to set in the West causing day and night.
This is a cycle.
d. The earth revolves around the sun in an orbit. One
revolution = approximately 365 days = 1 year
e. The moon revolves around the earth. The moon goes through phases where it looks
small or large depending on the time of month. The time it takes the moon to revolve
around the earth gives us our unit of time measurement-the month.
f. Tides are mainly due to the gravitational pull of the moon.
g. The same side of the moon faces Earth at all times. Thus there is a bright side and a dark
side. Come to the dark side Luke. This does not mean that the moon does not rotate, it
just means that from Earth we see no rotation. The moon has no atmosphere and no
water, this is why there are so many craters: no atmosphere to burn up asteroids- no
wind or water to erode and smooth the surface. Review moon phases.
h. Earth is tilted on its axis. This is what creates the seasons. When the southern
hemisphere is tilted toward the sun it is summer in the southern hemisphere. In the
northern hemisphere is tilted toward the sun is summer in the northern hemisphere.
i. The sun is the center of our solar system: although the sun does not have an
atmosphere like the planets, it has a solar atmosphere. 1 million times the size of Earth.
A nuclear furnace. Its surface frequently explodes. Extremely hot: hotter than the
already superhot core of the earth.
j. The sun provides almost all of the energy on earth, without it there would be no life on
earth. It provides electromagnetic energy which includes visible light, heat (infrared
light) and everything else on the electromagnetic spectrum. The most dangerous of the
sun's rays don't reach us because of the Earth's magnetic field. Aurora borealis.
k. Tbhe sun is the center of our solar system, but is not the center of the universe or even
our own galaxy.
l.
m.
n.
8. LIFE SCIENCE
a. Living things grow and change, need food, air and water as well as
space, can reproduce themselves, react to stimulus.
b. Life cycles and metamorphosis. Complete – butterfly and beetle;
incomplete - grasshopper
c. One element makes life possible. Carbon. Carbon is absorbed by
plants during photosynthesis, is used to make sugar which is then
turned into other chemical compounds that make up the plants
body. During photosynthesis plants give off oxygen which they
separate from the carbon in carbon dioxide. Animals need oxygen
and use it in the process of respiration. Animals release carbon
dioxide into the air. Which is then available for plans to use. THIS IS
THE CARBON CYCLE. Remember-animals can't live without plants
and plant can't live without animals.
d. Scientists call living things organisms. Organisms have basic needs. Plants need carbon
dioxide water and a place to live. Animals need oxygen, which is made by plants, food,
water, and shelter or a place to live. Organisms live in communities which are made up
of populations.
e. All organisms must adapt to their environment. If their environment changes they must
get M A D- move adapt or die. Organisms all have a habitat. Optimal habitat. Range.
f. All organisms have a niche-a job or place in the ecosystem where they live.
g. Ecosystem-anyplace with biotic and abiotic factors. It can be very large or it can be very
small.
h. Animals (including humans) all compete for food water and habitat.
i. Animals that cannot compete either die or are forced into new habitats which require
them to adapt.
j.
Adaptations may be physical-inherited-you are born with it or behavioral-learned
actions-you are not born with it but learn it after birth. Examples: morphology = how
you physically look = inherited. A dog riding a bicycle = learned.
k. Physical adaptations are inherited (passed down) from parents.
l. Within a species (type of organism) there are VARIATIONS which gives certain members
of the species advantage over others. This results in evolution through which one
species of animal changes over many years until it becomes a new species. Think of
ancient ancestors of giraffes becoming modern, long necked, giraffes.
m. Food chain-the arrows show the direction that energy is moving-up.
n. Food web-interconnected food chains-producers are always at the bottom, primary
consumers next, secondary and tertiary consumers follow up to an apex predator.
o. Energy pyramid-shows that there is more energy at the bottom than the top, and that
each step up the pyramid reduces the available energy. This is why we must have
millions of producers for a few herbivores, and even fewer predators.
p. In organisms place in the food chain is its niche. Main niche is: producer, primary
consumer (herbivore), secondary consumer (predator)
q. In a complex food web there may be tens of thousands of organisms all interlinked by
the transfer of energy from one to the other. Damage to anyone can result in damage to
many.
r. Key terms to know: habitat loss (destruction), endangered, extinct,
9. GENERAL THEMES TO UNDERSTAND:
a. cycles
b. systems
c. change and constancy
d. the interrelationship of all things