SOL science prep 8th grade Flashcards
the total amount of matter in an object
mass
can occur at surface of liquid without heating (eventually a cup of water will evaporate if left unattended
Evaporation
change from solid to gas
Sublimation
matter that is composed of one type of atom
element
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model which shows electrons traveling in specific energy levels around a nucleus, electrons closest to nucleus have low energy, electrons farther away have high energy
Electronic Cloud
an atom of an element that has a different number of Neutrons
Isotopes
uses the element symbol and dots to repersent outer energy level electrons
Electron Dot Diagram
Where are metals on the periodic table?
left side
malleable and ductile
metals
what does malleable mean?
can be hammered into sheets (think: malleable=mallet)
what does ductile mean?
drawn/made into wires
do metals or metalloids or non-metals have few electrons on the outer level (valence electrons)
metals
all but mercury are solid at room temperature
metals
where are non-metals on the periodic table?
right side
more than half are gasses at room temperature
not meteable
not ductile
non-metals
where are metalloids on the periodic table?
found along or touching the staircase
have properties of both metals and non-metals
have about a half complete set of valence electrons
metalloids
as elements go from left to right they get less reactive
1-7 of them
go from left to right
follow a repeating pattern
rows (periods)
similar chemical and physical properties
1-18
ones is same section have same number of valence electrons
columns (groups)
what groups are highly reactive
1, 2, 17
what group is Alkali Metals
1
what group is Alkaline Earth Metals
2
what group is the Halogens
17
what group is the Noble Gasses and are unreactive because outer energy level is full
18
what groups are transition metals. often occur in nature uncombined
3-12
substance made of the combined atoms of 2 or more elements
compound
two or more atoms combine to form a new substance that has new properties (physical or chemical) than the original elements
Chemical Bonding
tells what elements a compound contains and the number of atoms
Chemical Formula
when 2 or more Ions conbine to form neutrally charged compound
Ionic Bonding
the need to have a full outer ring or energy level
octet rule
an atom that has gained or lost electrons to have a full outer ring (now will be happy
Ion
charge an atom gets after gaining or losing electrons
Oxidation
when 2 or more atoms share valence electrons
electrons are shared
occurs between 2 nonmetals
nonmetals do not give up electrons
Covalent Bonding
substance that produces hydrogen ions (H+) in solution
Acid
what are the four properties of acids?
taste sour
are electrolytes (can conduct electricity)
corrosive
indicators to produce a predictable color change (red)
substance that produces hydroxide ions (OH) in solution also accepts H+ from acids
base
what are the 5 properties of bases?
in undissolved states, many are crystalline solid (feels slippery)
bitter taste
strong bases are corrosive
react with indicators (blue)
compound formed when negative ions of an acid combine with positive ions from a base
salt
0-2
ionizes almost completely in water
strong acid
3-6
only partly ionized in solution
weak acid
12-14
dissociates completely in solution
strong base
8-11
does not completely dissociate
weak base
measure of concentration of H+ ions in a solution or how acidic or basic it is
typically ranges from 0-14
pH
mixture in which 2 or more substances look the same
Homogenous
energy an object has due to its motion or position
Mechanical energy
energy from waves
Light/Radiant energy
refraction
diffraction
reflection
interference
a repeating movement or disturbance that transfers energy through matter or space
wave
matter through which a wave travels
medium
waves that can only travel through medium
Mechanical Waves
a measure of energy in a wave, the more energy a wave carries, the greater amplitude
amplitude
the angle of incidence of a wave is always equal to the angle of reflection
law of reflection
occurs when a wave strikes an object and bounces of it, all types of waves can be this
reflection
bending of wave caused by a change in its speed as it moves from one medium to another
refraction
an object causes a wave to change direction and bend toward it
diffraction
when two or more waves overlap and combine to form a new wave
interference
waves subtract
Destructive
waves add
Constructive
1?
rarefaction
2?
compression
3?
wavelength
1?
Rest Position
2?
Amplitude
3?
Crest
4?
Wavelength
5?
trough
made by vibrating electric charges and can travel through space
electromagnetic waves
low frequency waves with wavelength of about 1-10 cm
Radio Waves
have slightly higher frequency than radio waves
Infared waves
range of electromagnetic waves you can detect with your eyes
Visible Light
frequencies slightly higher than visible light
Untraviolet waves
ultra, high frequencies that can travel through matter, domage cells
X rays & Gamma Rays
transfer of thermal energy by collisions between particles in matter
Conduction
transfer of thermal energy in a fluid by movement of warmer and cooler fluid from place to place
Convection
transfer of energy by electromagnetic waves
Radiation
a potential difference between 2 places causing electrons to flow
voltage
what is the unit of energy
Joules (J)
the ability to cause change
energy
a path in which electrons from a voltage or current source flow
Circuit
what is newton’s first law?
an object in motion stays in motion or an object at rest stays at rest until an unbalanced net force acts upon it
tendecy of an object to resist any change in its motion
more of this more mass
Inertia
what is newton’s second law of motion?
a net force acting on an object causes the object to accelerate in the direction of the force
what is newtons third law of motion?
for every action there is an equal and opposite reaction
does acceleration change direction?
yes
the ratio of the output force to the input force
Mechanical advantage
measure of how much work put into a machine is changed into useful output work by the machine
efficiency
fulcrum between the input force and output force
1st class lever
output force is between fulcrum and input force
2nd class lever
input force is between fulcrum and output force
3rd class lever
pulley attached to something that doesn’t move
fixed pulley
pulley, one end of the rope is fixed and the wheel is free to move
moveable pulleys
system of pulleys consisting of fixed and moveable pulley
block and tackle
occurs when a force causes an object to more in the same direction as the force
work
what are the two questions you ask to know if something is work
Does the object move?
Is the direction of motion the same as the direction of force applied?
