physical science vocab
physical science vocabulary
Terms
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- Newton's Second Law of Motion
- an unbalanced force acting on an object equals the objects mass times its acceleration (F=ma)
- work
- quantity of energy transferred by a force when it is applied to a body and causes that body to move in the direction of the force; = force times distance (=Fd); measured in joules
- absolute zero
- physically the lowest possible temperature: -273.13 degrees celsius enery is minimal
- covalent bonds
- share electrons (primarily nonmetal and nonmetal), molecules, low melting point, bad conductor of electricity
- mechanical energy
- sum of potential energy and kinetic energy of large scale objects in a system
- precipitate
- an insoluble compound formed in a reaction; usually a solid
- control group
- group in experiment that is exact same as experimental group, but does not include variable
- Newton's First Law of Motion
- an object at rest remains at rest and an object in motion maintains a constant velocity unless it experiences an unbalanced force equal to zero (when net force =0)
- Celsius-Kelvin conversion
- Kelvin temperature=Celsius temperature + 273
- atom
- basic unit that makes up all matter, composed of protons, electrons, and various numbers of neutrons
- Archimedes's principle
- a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid
- indicator
- a compound that can reversibly change color in a solution, depending on the consentration of H3O+ ions
- air resistance
- friction resisting the movement of an object through air
- centi
- 0.01; symbol is "c"
- Avogadro's constant
- number of particles in one mole; 6.022 times 10 to the 23 power
- organic compound
- covalently bonded compound made of molecules; contains carbon and almost always hydrogen
- pH
- a measure of the hydronium ion concentration in a solution
- base
- pH >7; usually have OH polyatomic ion, produce OH- ions in a solution; conduct electricity (electrolyte), dissolve fats, soapy, bitter
- nonmetal
- found on right side of periodic table (except hydrogen); may be solids, liquids, or gases; typically dull and brittle; poor heat/electricity conductors
- buoyant force
- the upward force exerted on an object immersed in a fluid by the fluid
- salt
- an ionic compound; formed with a neutralization reaction between an acid and a base; positive metal from base and negative nonmetal from acid
- atom
- basic unit that makes up all matter, composed of protons, electrons, and various numbers of neutrons
- Bernoulli's principle
- as the velocity of a fluid increases, the pressure exerted by the fluid decreases
- compound
- substance made of atoms of 2 or more elements; can be separated by chemical means, but not by physical means; properties are different from atoms that make it up; can only be changed by chemical chance involving the valence electrons
- 2 things machines can do
- multiply forces; redirect forces
- atomic number
- the number of protons in an atom; identifies the atom
- boiling
- when liquid becomes a gas below the surface
- crystal
- made up of many solids and are arranged in a regular repeating pattern; solids made up of these are called crystalline solids; solids with particles not arranged in a regular repeating pattern dont keep definite shapes permanently are called amorphous
- combustion reaction
- a reaction in which a compound and oxygen burn; oxygen is always a reactant and at least one product contains oxygen
- pressure
- the amount of force per unit area (=F/area)
- area
- used to represent size of objects in length and width (for flat objects); height is inclued for 3D objects; unit is meters squared
- acid
- pH<7, usually have hydrogen; produce H+ ions in solution (aq) which combines with H2O to form hydronium ions(H3O+); conduct electricity (electrolyte); are corrosive; react with many metals releasing hydrogen gas; tastes sour
- centripetal force
- the force acting on an object accelerating an object towards the center of a circle
- ionic compound
- high melting points, conducts electricity, brittle, crystal structure, repeating positive and negative ions
- metals
- most elements are this; most are shiny solids that can be stretched and shaped; good conductors of electricity and heat; found on left side of periodic table
- kinetic energy
- depends on square of objects speed; small increase in speed = large increase in this; = one half mass times velocity^2
- acceleration
- change in velocity over time; any change in velocity requires an unbalanced force
- condensation
- the change of a substance from gas to liquid
- atom
- basic unit that makes up all matter, composed of protons, electrons, and various numbers of neutrons
- Boyle's Law
- the volume of a fixed amount of gas varies inversely with the pressure of a gas; as the volume of a gas decreases the pressure increases; if the volume increases, then the pressure decreases; one of the gas laws
- potential energy
- stored energy resulting from relative positions of objects in a system; sometimes called energy of position; depends on mass and height; = mass times freefall acceleration times height ( =mgh)
- anhydrous
- without water; gains water molecules easily
- Charles's Law
- the volume of a fixed amount of gas varies directly with the temperature of the gas; if the temperature of a gas increases, the volume increases; one of the gas laws
- specific heat
- amount of thermal energy needed to raise temp of 1 kg of material 1 Kelvin; Change in thermal energy = this times mass times change in temperature)
- mechanical advantage
- quantity that measures how much a machine multiplies force or distance; ratio between output force and input force and = to ratio between input distance and output distance; output force over input force= input distance over output distance; machine with this greater than one multiplies input force, but less than one increases distance and speed
- Avogadro's law
- relates the number of particles of a gas to its volume; equal volumes of gases at the same tmperature and pressure contain equal numbers of particles or moles; called the gas law
- Newton's Third Law of Motion
- the law of action and reaction; for every force there is an equal and opposite reaction force
- atomic number
- the number of protons in an atom; identifies the atom
- balanced forces
- forces acting on an object that combine to produce a net force equal to zero
- kinetic theory of atomic and molecular behavior
- atoms and molecules move faster and therefore collide which can lead to chemical reactions; an increase in temperature yields an increase in kinetice energy which yields an increase in the number of reactions; an increase in surface area yields an increase in the number of reactions; an increase in concentration yields an increas in the number of reactions
- area of a circle
- pi times radius squared
- atomic number
- the number of protons in an atom; identifies the atom
- factors affecting reaction rates
- increase in temperature, surface area, concentration of solutions, size/shape, catalysts
- Avogadro's constant
- number of particles in one mole; 6.022 times 10 to the 23 power
- alkali metals
- soft, shiny, reacts violently with water; 1 easily removed valence electron; not found in nature as elements, but combine to form compounds; 1st group on the periodic table
- efficiency
- useful work output divided by input work, times 100 with a %
- power
- a quantity that measures the rate at which work is done (how much work is done in a certain amount of time) = work divided by time (w/t) measured in watts
- area of rectangle
- length times width
- Avogadro's constant
- number of particles in one mole; 6.022 times 10 to the 23 power