Science OGT Flashcards
Newtons 1st law:
A body at rest remains at rest and a body in motion remains in
motion until an outside force acts on it (inertia).
Newtons 2nd Law
A force causes an object to accelerate.
F= mass x acceleration
Kinetic energy
Energy in motion
examples: someone jogging, an mp3 player playing music. You can
calculate the kinetic energy of moving objects by using the equation:
Kinetic Energy = 1/2 mass (velocity)^2
Potential energy
Stored energy; the ability of a system to do work
due to its position or internal structure.
examples: A battery, the food we eat for energy, a rock on a ledge of a
mountain, and a expanded rubber band.
GPE= m x g x h
g= 9.8m/s
The Law of conservation of energy:
energy cannot be
created or destroyed only converted to another type of energy
Friction
the rubbing of one object or surface against another
.Conduction
Transfer of heat through a solid object from a source
ex. When water is boiled over a fire or on the stove, the flames don’t
directly heat the water. The heat of the flame is conducted through
the metal, then to the water
Convection
Transfer of heat by liquid or gas.
When water boils on the stove, it becomes gas that heats up the air
above it (transfer of heat by gas)
Radiation
Heat transferred by electromagnetic waves.
Electromagnetic waves
all waves of energy including visible light,
microwaves, infared, x-rays, & radio waves.
The sun radiates heat to earth. A microwave radiates heat to food,
and a campfire radiates heat to warm you
Gravity
Gravity will accelerate all objects at the same rate regardless of their
mass. This is why a marble and a bowling ball when dropped from a
building will hit the ground at the same time
Physical properties
all properties that can be determined without
changing the identity of the substance, such as color, density, phase
(liquid, solid, or gas), odor, boiling & freezing points and solubility (can
it dissolve in another substance such as sugar in water?).
Chemical properties-
A characteristic that a substance displays when it
changes into a new substance.
Physical Change
A change that does not create any new substance.
EX. Phase changes of water are all physical changes. Boiling or
freezing water does not create a new substance. If you cool the boiling
water or heat up the ice you will still have water.
Chemical Change
– Any change that produces a new substance.
when something is burned, such as paper or gasoline, there is
a new substance being formed carbon dioxide.
• when iron rusts it combines with oxygen to produce iron
oxide, a new chemical.
Endothermic
A reaction that absorbs heat from the surrounding.ex. Melting an ice cube is an endothermic process because heat is
being absorbed to change ice into liquid water.
Exothermic
- A reaction that gives off heat
ex. Burning wood or paper produces heat
Freezing
When a liquid becomes a solid. Molecules become packed
tighter together moving less.
Melting-
Occurs when a solid changes to a liquid allowing molecules to
move more freely
Evaporation-
When a liquid becomes a gas. The molecules are now
moving very rapidly.
Condensation-
- When a gas becomes a liquid. This occurs on a cold
glass beverage on a warm day and this is also how clouds are formed.
Sublimation-
when ice goes directly into gas form skipping becoming a
liquid phase.
ex. Dry ice at room temperature will turn into a gas without becoming a
liquid first
Precipitation-
During the water cycle, when clouds can no longer hold
all the water from condensation, the clouds will release the water in the
form of rain or snow
Density
Density= mass / volume ,The density of water is 1 g/ml.
matter
anything that takes up space. Matter is
made of atoms or various atoms combined
Atom:
Smallest particle of an element that has all the properties
of that element.
Element:
a pure substance that cannot be broken down into a
simpler substance.Elements contain only one type of atom.
Atom parts
Protons have a positive charge, neutrons have no charge & electrons
have a negative charge,Protons & neutrons combine to form the nucleus of the atom and
electrons orbit around this nucleus.
atomic numbers
# of protons in an atom of that element.
Atomic mass
the # of protons plus the # of neutrons.
Wavelength:
The length of one complete wavelength cycle., peak to peak or crest crest
Amplitude:
A measure of the energy a wave carries. It’s determined by
the distance from the crest or trough to the midline (or resting wave).
The larger the amplitude the higher the sound
Frequency:
The # of waves that pass a point in a given amount of time, less waves in a given time= lower frequency, more waves in a given time= higher frequency
The Big Bang Theory
The universe was created in one giant explosion
about 13.7 billion years ago, and is constantly expanding even today
from this location
Two observations that help support the Big Bang Theory are..
♦ galaxies are moving apart from a central location.
♦ red shift- The light most galaxies give off is close to the red
end of the spectrum because as they move farther out, the
energy becomes weaker & stretched out. This light energy is
longer and is the color red.
nebula
In space, dust & gas get pulled together by gravity The nebula, depending on its size, becomes a massive star or a low mass
(smaller) star-
nuclear fusion
causes hydrogen protons to join together producing the
massive energy just as our sun does
Telescopes-
with optical telescopes, astronomers see closer the objects
in outer space such as moons, planets, galaxies.
Spaceship
- allows astronauts to travel to close planets, our moon & into
outer space to collect data and experience first hand the conditions in
space.
Satellites-
Are used to transmit signals from outer space such as
pictures, topographic maps. Just like cell phone satellites allow our
signals to travel from place to place.
Probes-
are sent by scientists to collect data on far away planets that
humans can never get to. Probes send data back by signals & some even
retrieve samples from planets
Galaxies
large group of stars. There is said to be a billion of them
in the universe.
Our solar system- the sun, our earth and the 8 others belong to the Milky
Way Galaxy
There are 3 different kinds of galaxies. Galaxies are characterized by
their shape.
1). Spiral →
2). Eliptical →
3). Irregular
e Law of Universal Gravitation
says between
any two objects there is attraction (gravity) that is proportional to the
masses of the objects and the distances between them.
more massive an object is, it has a stronger pull of
gravity on objects that are less massive than itself. Our sun is more
massive than the planets so they all revolve around the sun.
Our planet earth is more massive than our moon so this is why the
moon revolves around our earth
Earth revolving around the sun
The earth rotates on its axis. This brings diffent parts of the earth in
contact with the sun → The reason we have night & day!The reason the sun appears to “rise in the east” is because that’s the way
our earth rotates, bringing the eastern part of the U.S. in contact with the
sun first.
One complete revolution of the Earth around the sun takes one year.
Seasons:
When the Earth revolves around the sun it also tilts. This tilting of
the Earth brings places such as Cleveland, OH. in direct contact w/ the
sun’s hottest direct rays during our summer. During winter for Cleveland
(and other places in the northern hemisphere), we are tilted out of
contact with these hottest rays. This is why it gets cold. We still get
sunlight in Cleveland during the winter but these rays are not the hot
direct rays like in summer.
Places along the equator are hot year round because they don’t move from the direct rays of the sun, just like the N and S pole never get hit, When the N hemishper is having winter the south is having summer
Solar eclipse
occurs when the moon either partially or completely
blocks the sun from the Earth’s view.
Lunar eclipse
- occurs when the Earth blocks our view of the moon. A
lunar eclipse can only occur during a full moon.
Plate tectonics
Is the theory that the Earth’s crust is made up of many
plates that are floating on top of the Earth’s mantle layer which is molten
liquid rock. These plates interact with each other in many ways…
When these plates slide past each other creating friction,
earthquakes can occur.
. When Earth’s plates collide & push up they can create mountain
range
. Magma from mantle can erupt past space between 2 plates or melt
through a soft crustal plate
The crustal plates sit on the mantle layer of the Earth. The mantle
is liquid hot rock that convection currents. These convection
currents push the plates around causing continents to drift & seafloors to spread.
Alfred Wegener
proposed the continental drift theory saying that at
one time all continents joined together in a single land mass.
The main observation that supports his theory is that 1)identical fossils
of an animal were found on different continents, 2)identical rock layers
(formations) were also found on many continents & 3) continents fit
together like a puzzle.
Fossils
A piece or trace of an organism that was once alive. They are mainly
found in sedimentary rocks
cross-sections
of rock layers from different continents are identical.
This also supports his theory of continental drift. This means the
thicknesses & types of minerals match up identically from many
continents. Know that rock sediments get laid down such as in a lake or ocean bed,
the oldest rock is at the bottom, because it was laid down first.
fossil fuels.
Fossil layers of the Earth are our source of fossil fuels. These organisms
turned into carbon which we use as fuel. They include gasoline, oil and
coal. Fossil fuels are considered nonrenewable resources because we
can never replace or renew them. They took millions of years to form
Renewable resources
however can be replaced and renewed. Sunlight,
water power,wind, wood, crops are all renewable resources
Global warming
g is the planet becoming warmer through out the years. The Earth has an insulation layer of CO2 in its
atmosphere that helps keep warmth from the sun in. This layer is thin
enough to allow some heat to escape so are planet does not get too hot.
This is called the Greenhouse Effect. When fossil fuels & wood are
burned they give off carbon dioxide (CO2) which causes the insulation
layer to be too thick so now too much heat is trapped not being allowed
to escape. This causes GLOBAL WARMING!!
conservation.
recycle
♦ car pool
♦ riding a bicycle instead of driving.
♦ use public transportation.
♦ turn off water and electricity when were not using them.Biomes
are places on Earth that have distinct climate
(how much rainfall they receive and their temperatures) and types of
plants and animals that thrive in these specific climate.
Biomes with colder temperatures have less amount of life living there.
This is the same reason Alaska is not as populated with humans as
California or Mexico
♠ The more heat & precipitation means more plants and more life.
Desert
Little rain & large daily change in temperature (hot in the day
& cold at night).
Rainforest
Lots of rain with hot temperatures
Tundra
Has dry & wet seasons but very cold
Grasslands
Has dry & wet season. Temperature is hot
Deciduos forest
Moisture evenly distributed throughout year. Has warm summers and cold winters.
Coniferous Forest
Moisture varies throughout year. Has cool summers & cold winters
Weather-
- conditions in our atmosphere such as temperature, sunshine,
rain, snow and clouds.
sun is the main cause of weather. We learned earlier how the sun
creates warm parts of the Earth by its direct rays. Certain materials heat
up differently. Darker objects will absorb heat from the sun better than
light ones, which reflect the heat better. This is why asphalt parking lots
can be so hot in the summer
These different surfaces of the Earth will heat up at different rates
causing hot air to rise & cool air to sink. When this happens wind
occurs.
Climate
Amount of precipitation and the temperature an area gets
throughout the year.
Moh’s hardness scale
categorizes the hardness of minerals. Hardness is
the resistance of a mineral to being scratched. These minerals are
numbered 1thru 10. 1 being the softest mineral on Earth & 10 being the
hardest meaning nothing else can scratch a #10If a mineral has a higher # than another mineral, then the higher # will
scratch the lower one.
Predator
organisms that kill and eat other organisms
Prey:
The organisms the predator kills and eat
Herbivore
An organism that feeds off of plants only.
Carnivore
An organism that feeds off of animals only
Omnivore
An organism that feeds on plants and animals.
ex. Most humans, raccoons
consumers
because they have to
consume other organisms (plants or animals or both) to get their energy
photosynthesis
Plants produce their own food by using sunlight in a process
producers.
Plants
primary consumer
A herbivore is considered a primary consumer because it is the first
organism to consume the plants.
secondary
consumer.
An animal that eats the primary consumer
Biotic factors
are living organisms in the environment.
ex. For the rabbit, flowers, hawks and other living organisms are all
factors the rabbit has to deal with`
Abiotic factors
are all nonliving things in an environment.ex. For the rabbits’ environment, abiotic factors include weather, rocks,
water, hills, rocks & holes they can hide in
