8th Grade Science Final - part 4
Terms in this set (43)
Ability to do work
The energy an object that is due to its motion
kinetic energy = mass x velocity /2; mv /2
The energy that an object has because of the position, shape, or condition of the object
a change from one form of energy to another
law of conservation of energy
the law that states that energy cannot be created or destroyed but can be changed from one form to another
a resource that forms at a rate that is much slower than the rate at which the resource is consumed
examples of nonrenewable resources
fossil fuels, nuclear energy
a natural resource that can be replaced at the same rate at which the resource is consumed
examples of renewable resources
solar, geothermal, hydroelectric, wind, biomass
the smallest particle into which an element can be divided and still be the same substance
developed the atomic theory
A. All substances are made of atoms
B. Atoms are small particles that cannot be created, divided or destroyed
C. Atoms of the same element are exactly the same.
D. Atoms of different elements are different.
E. Atoms join with other atoms to make new substances
the center of the atom which is composed of 2 types of particles - protons and neutrons
positively charged particles in the nucleus
particles of the nucleus that have no charge
Tiny, negatively charged, high-energy particles that move around outside the nucleus of an atom in the electron clouds
electrically charged particles;
Substances in which at least one atom has an imbalance of protons and electrons
The number of protons in the nucleus of an atom
An atom with the same number of protons and a different number of neutrons from other atoms of the same element.
The weighted average of the masses of all the naturally occurring isotopes of an element
wrote the first periodic table organized by increasing atomic mass, vertically, and separated by similar properties
the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements
Most elements are metals
- most found to the left of the zigzag line
- shiny, malleable, ductile, good conductors of thermal energy and electricity
found to the right of the zig zag line
dull, not malleable, not ductile, poor conductors of thermal energy and electricity
Also called semiconductors
Elements that have some properties of metals and some properties of nonmetals
The elements just on either side of the zigzag line on the periodic table
A horizontal row of elements in the periodic table-
Where are most reactive elements located on a periodic table?
on far left (alkali metals)
Where are least reactive elements located on a periodic table?
far right (noble gases)
A vertical column of elements in the periodic table; elements in a group share chemical properties.
A substance through which a wave can travel
can be a solid, liquid or gas
waves that require a medium through which to travel
waves that transfer energy without going through a medium
A wave in which the particles of the medium move perpendicularly to the direction the wave is traveling
The highest point of a transverse wave
The low point between each crest of a transverse wave
a wave in which the particles of the medium vibrate parallel to the direction of wave motion
The part of a longitudinal wave where the particles of the medium are crowded together.
a part in a longitudinal wave where the particles are spread apart
The maximum distance that the particles of a wave's medium vibrates (moves up or down) from its rest position.
The distance from any point on a wave to an identical point on the next wave
the number of waves produced in a given amount of time
The bouncing back of a wave after it strikes a barrier or an object
Bending of a wave as it passes from one medium to another at an angle
The bending of waves around a barrier or through an opening