Science Flashcards
What are galaxies
millions or billions of stars are held together by gravity by gas and dust
explain the life cycle of an average star
it starts in the stellar nebula and goes onto average star then red giant then planetary nebula then white dwarf
explain the life cycle of an massive star
it starts in the stellar nebula and goes onto massive star then red super giant then a supernova then black jole/ neutron star
what is a nebula
cloud of gas and dust —–> stellar nursery
what is a protostar
gravity makes gas condense gathering mass
how is a main sequence star in high and low mass
high- burns fuel faster(stars spend most of their time here)
low- once the temperature is hot enough it makes nuclear fusion
describe a supergiant
much larger than a red giant
describe a red giant
hydrogen fuel depleats care contracts outer expanders
describe a supernova
core collapses rapid fusion reaction explodes energy that makes heavy elements
describe a planetary nebula
the outer layers of the star sheds and creates a nebula of gas
white dwarf
dense, earth size, gradually cools
black hole
big fat hole that has so much gravity that light can’t escape
what does the tempature for stars mean
blue=hot red=warm
\what is the charge of protons neutrons and electrons and how do you find them
protons= positive
electrons= negative
neutrons=neutral
Atomic number=protons/electrons
Atomic mass- number= neutron
what is matter and 3 examples
anything that takes up space ex.: tree’s air dogs
what is volume
amount of space matter takes up
what is the difference between chemical change and physical
chemical is when the substance changes while physical changes appearence
what is force
A push or a pull on an object; the unit of force is the Newton (N)
what is the difference between contact and non contact force
Contact is morre Force-touching and a example is Physical Push or Pull,
Non-Contact is long distance pull-exerted without contact a example is Magnetism, Gravity
what is friction force
contact force that acts to oppose a sliding motion between surfaces
what is normal force
Contact force exerted by a surface onto an object
what is spring/elastic force
the force a spring or rubber exerts on an object
what is tension force
the pull exerted by a string, rope or cable when attached to a body and pulled tight
what is thrust force
A general term for the forces that move objects such as rockets, planes, cars and people
what is buoyant force
the upward force exerted by any fluid upon a body placed in it
what is gravity/weight force
long range force due to gravitational attraction between 2 objects (generally the earth and a 2nd object). The Earth is pulling all objects on it toward it´s center.
what is air resistance/drag force
force of friction between the air and an object traveling through the air
what is magnetic force
force of attraction or repulsion between North and South Poles of a magnet
what is Electrostatic force
force of attraction between positive and negative electric charges
what is rate
a measurement of how much something changes in a certain unit of time
what is speed and its formula
the distance an object travels in a unit of time, such as seconds
s=d/t
what is velocity
a measurement that includes the speed of an object and its direction.
what is acceleration
the rate of change of an object’s velocity over time.
what is newtons 1st law
- an object moving will keep moving
- an object at rest will stay at rest
what is newtons 2nd law
the acceleration of an object is in the same direction as the net force on the object.
what is newtons 3rd law
“For every action there is an equal and opposite reaction.”
what are the layers of the earth
crust, mantle, outer core, inner core
what is the crust
and 2 types of it
the thin and solid outermost part of the Earth. Made mostly of silicon, oxygen, and aluminum. The thinnest layer of the Earth
Oceanic (the ocean floor) and Continental (dry land). Oceanic Crust is more dense and thinner than Continental crust.
what is the mantle
the layer of the Earth right underneath the crust. It is the thickest and largest layer. Made of aluminum, silicon, magnesium, and some iron. The uppermost part of the mantle is solid. Most of the mantle thought has a fudgy consistency. It is where magma comes from.
what is the outer core
layer of the Earth underneath the Mantle. Made of liquid iron and nickel.
what is the inner core
innermost layer of the Earth under the outer core. It is made of solid iron and nickel. It is the densest layer of the Earth
what is the lithosphere
the solid, outermost layer of the Earth that consists of the crust and the rigid solid upper part of the mantle.
what is the asthenoshpere
the soft fudgy layer of the mantle on which the lithosphere floats on.
what are convection currents
the transfer of heat by a fluid (liquid or gas)
what are plate boundaires
Location where two tectonic plates meet
Changes to Earth’s surface occur near plate boundaries
what are the different type of plate boundaries
3 types of plate boundaries – Convergent, Divergent, and Transform
what is convergent boundry
and what happens when different types of crusts collide
When two plates are moving toward one another
Old crust is destroyed/recycled
This is when the plates converge (collide)
continental vs. continental
When two continental crustal plates collide
The continents buckle upward and form mountains.
oceanic vs.contienental
The more dense oceanic plate subducts under the less dense continental plate.
The continental plate sinks into the asthenosphere (upper mantle) where it is melted back into magma.
Forms volcanoes, volcanic arcs and/or trench.
oceanic vs. oceanic
Two oceanic plates collide
The more dense oceanic plate subducts under the less dense one.
Forms a volcanic island, volcanic island arc and/or a trench
Also called a subduction zone
what is divergent boundary
and what happens when different types of crusts collide
When two plates are moving away from one another
Magma rises and spills out from under the plates, making new crust
Sometimes referred to as sea floor spreading
Land form(s) created: mid-ocean ridge or rift valley
continental vs. continental
When two continental crustal plates collide
The continents makes a ridge
what is a transform boundry
When two tectonic plates slide past each other
Movement between two plates is not smooth; pieces of plates get “stuck”, when they break away from one another the built up energy is released
Produces faults and Earthquakes
What is a tophographic map
three-dimensional arrangement of physical attributes (such as shape, height, and depth) of a land surface in a place or region.
how does heat transfer to us and what is the main source
conduction convection radiation
our main source is the sun
