 | Term | Definition |
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volume |
The amount of space that matter occupies |
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density |
The measurement of how much mass of a subtance is contained in a given volume |
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mass |
A measure of how much matter is in an object |
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weight |
A measure of the force of gravity on an object |
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element |
A substance that cannot be broken down into another substance by chemical or physil means |
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compound |
A substance made of two or more elements chemically combined |
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period |
A row of the periodic table |
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group |
A column of the periodic table |
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symbol |
One- or two-letter symbols identify elements |
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atomic number |
The number of protons in an atom's nucleus |
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atomic mass |
The average mass of an element's atoms |
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History of Periodic Table |
mendeleev discovered repetiton of properties. So he placed the cards for the elements into a group. He moved the cards into groups where they fit best according to atomic mass. He left three blank spaces for new elements. He even predicted the properties of those new elements. He published the first periodic table in 1869. Within 16 years, chemists discovered the three missing elements, named scandium, gallium, and germanium. Their properties are close to what Mendeleev predicted. |
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ion |
An atom or group of atoms that is electrically charged |
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Atom Structure |
An atom consists of a nucleus surrounded by one or more electrons. the electrons can either be protons or nuetrons. |
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covalent bond |
A chemical bond formed when two atoms share electrons |
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ionic bond |
The attraction between two oppositely charged ions |
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endothermic reaction |
A reaction that ABSORBS energy in the form of heat |
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exothermic reaction |
A reaction that RELEASES energy in the form of energy |
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acid |
A substance that tastes sour, reacts with metals and carbonates, and turns blue litmus paper red |
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base |
A substance that tastes bitter, feels slippery, and turns red litmus paper blue |
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polymer |
A large, complex molecule built from smaller molecules bonded together |
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Newton's First Law |
states that an object at rest will remain at rest and an object that is moving at constant velocity will continue moving at constant velocity unless acted upon by an unbalanced force |
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Newton's Second Law |
states that the net force on an object is equal t the product of its accelerated and its mass |
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Newton's Third Law |
states that if one object exerts a force on another object, then the second |
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balanced forces |
Equal forces acting on an object in oppisite directions |
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unblanced forces |
A nonzero net force that changes an objects motion |
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speed |
The distance an object travels in one speed of time |
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speed (formula) |
Speed= Distance/Time |
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acceleration |
The rate at which velocity changes |
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acceleration (formula) |
Acceleration= Final Velocity-Initial Velocity/Time |
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centripetal force |
A force that causes an object to move in a circle |
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Boyle's Law |
The relationship between the pressure and volume of a gas at constant temperature; when volume increases, pressure decreases |
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Charles's Law |
The relationship between the temperature and volume of a gas at constant pressure; when teperature increases, volume increases |
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Bernoulli's Principal |
The rule tha a stream of fast-moving fluid exerts less pressure than the surrounding fluid |
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Archimede's Principal |
The rule that the buoyant force on an objetc is equal to the weight of the fluid displaced by that object |
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Pascal's Principal |
The rule that when force is applied to a confined fluid, the increase in pressure is transmitted equally to all parts of the fluid |
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Six Simple Machines |
There are six basic kinds of simple machines: the inclined plane, the wedge, the pulley, the lever, the wheel and axle, and the screw |
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energy |
The ability to do work or cause change, such as moving an object some distance |
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power |
The rate at which work is done or the rate at which one form of energy is converted into another |
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chemical energy |
The potential energy stored in chemical compounds |
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wave |
A disturbance that transfers energy from place to place |
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wavelength |
The distance between the crest of one wave and the crest of the next |
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transparent |
Term used to describe material that transmits light |
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translucent |
Term used to describe a material that scatters light as it passes through |
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opaque |
Term used to describe a material that reflects or absorbs all light that strikes it |
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electromagnetic spectrum |
The range of eletromagnetic waves |
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What is the electromagnetic spectrum made of? |
It is made up of radio waves, infrared waves, visible light, ultraviolet rays, X-rays, and gamma rays |
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radio waves |
They have longest wavelengths and shortest frequencies. Some examples are microwaves, radar, and MRI |
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infrared rays |
They have shorter wavelengths and higher frequencies than radio waves. An example is a thermogram. |
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visible light |
They have shorte wavelengths and higher frequencies than radio waves. This is the part of the spectrum you can see. Each different wavelength of light has a different color. |
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ultraviolet rays |
They have shorter wavelengths and higher frequencies than visible light. In small quanities, they help your body produce vitamin D. In larger quanities, they can cause sunburn or even skin cancer. |
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X-Rays |
They have shorter wavelengths and higher frequencies than ultraviolet rays. they can penetrate the body, but are absorbed by denser tissues, such as bone. These parts sho up as white on an X-Ray image. X-Rays that are not absorbed pass right through and cause the photographic film to darken when developed. |
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gamma rays |
They have the shortest wavelengths and the highest frequencies. they are used in hospital to diagnose cancer. They penetrate the body and are aimed at the tumor, killing it. Uncontrolled doses of gamma rays can cause cancer. |
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refraction |
The bending of waves as they enter a different medium |
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concave lens |
A lens that is thinner in the center than at the edges |
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convex lens |
A lens that is thicker in the center than at the edges |
