Physical Science Flashcards
Scientific Method
The method of making new discoveries.
Observation
The gathering of information.
Qualitative Observation
An observation about the quality of something. (hot, heavy, rough, etc.)
Quantitative Observation
An observation about the strength of a quality of something.(66 degrees Fahrenheit, 5cm, etc.)
Hypothesis
A possible, testable explanation for an observation.
Experiment
A way of testing a hypothesis.
Controlled Experiment
An experiment in which all variables are carefully controlled.
Variable
A factor that changes an experiment.
Independent Variable
A single variable which is intentionally changed.
Dependent Variable
A variable which varies depending on the value of the independent variable.
Scientific Theory
A set of hypotheses that explain a type of natural phenomenon
Scientific Law
A prediction/description of a natural phenomenon
Inference
A logical conclusion based on indirect evidence.
Scientific Model
A simplified version of an abstract or unobservable object or theory. Generally visual.
Unit
A set method of recording a measurement.
Metric System (SI)
The international system of measurement.
Mass
The amount of matter something has.
Gram
The SI unit of mass
Meter
The SI unit of length
Liter
The SI unit of volume.
Factor-Label Method
A method of unit conversion.
Extrapolation
A logical method of gaining extra information from a graph.
Matter
Anything that has mass and volume
Element
A pure substance that cannot be broken down into a simpler substance and contains only one kind of atom.
Atom
The smallest chemical unit of an element.
Compound
A pure substance that contains two or more elements chemically joined in a fixed proportion.
Molecule
The smallest unit of a chemical compound, composed of two or more atoms bonded together.
Mixture
Two or more substances mixed together but not chemically bonded.
Solution
A homogeneous mixture made by dissolving on substance in another.
Solute
The substance in a solution that gets dissolved.
Solvent
The substance in a solution that dissolves the other substance
Solid
The state of matter in which a substance has definite shape and volume.
Liquid
The state of matter in which a substance has a definite volume.
Gas
The state of matter in which a substance has neither a definite shape nor a definite volume.
Density
The ratio of a substance’s mass to its volume; defined by the equation: D = m/v
Diffusion
The natural movement within gases and liquids that spreads out particles from an area of higher concentration to an area of lower concentration.
Law of Conservation of Mass
Matter cannot be created or destroyed, but it can change forms.
Law of Constant Composition
Samples of a pure compound always have the same elements in the same mass proportion.
Atomic Number
The number of protons in an atom.
Mass Number
The sum of the protons and neutrons in the nucleus of an atom.
Isotopes
Atoms of an element with the same number of protons but different numbers of neutrons.
Orbitals
A region of space around the nucleus where electrons are most likely to be found.
Valence Electrons
Electrons that are in the highest energy level of an atom of an element.
Chemical Formula
A notation indicating the elements in a compound and the ratios of the atoms of each element.
Reactants
Substances that undergo a chemical change.
Products
New substances formed as a result of a chemical change.
Coefficients.
Numbers that appear before a formula in a chemical equation to show how many atoms or molecules of each reactant or product are involved in the reaction.
Chemical Bond
A force of attraction between atoms or groups of atoms.
Ion
An atom or a group of atoms that has a positive or negative charge.
Ionic Bond
A chemical bond formed between oppositely charged ions.
Covalent Bond
A chemical bond in which two atoms share one or more pairs of valence electrons.
Polar Molecule
A molecule that has slight positive and negative charges due to an imbalance in the way electrons are shared.
Cohesion
The force of attraction between molecules of the same substance so that they tend to stand together.
Adhesion
The force of attraction between molecules of different substances so that they tend to stick together.
Binary Compound
Compounds made of only two elements.
Polyatomic Ion
A covalently bonded group of atoms that has a positive or negative charge and acts as a unit.
Synthesis Reaction
A chemical reaction in which two or more substances react to form a single compound.
Decomposition Reaction
A chemical reaction in which a compound breaks down into two or more simpler substances.
Single Replacement Reaction
A chemical reaction in which one element takes the place of another element in a compound.
Double Replacement Reaction
A chemical reaction in which two compounds exchange positive ions and form new compounds.
Combustion Reaction
A chemical reaction in which a substance reacts rapidly with oxygen, often producing heat and light.
Chemical Energy
The energy stored in chemical bonds.
Mole
An amount of a substance that contains approximately 6.02*10^23 particles of the substance.
Exothermic Reaction
A chemical reaction that releases energy to its surroundings.
Endothermic Reaction
A chemical reaction that absorbs energy from its surroundings.
Reference Point
A point against which a direction is measured.
Displacement
The distance an object travels plus the direction from the starting point.
Vector Quantity
A physical measurement that contains both magnitude and directional information.
Scalar Quantity
A physical measurement that contains only magnitude information.
Average Speed
The ratio of the total distance traveled to the total time of the trip.
Instantaneous Speed
The rate at which an object is moving at a given moment in time.
Acceleration
The time rate of change of an object’s velocity.
Force
A push or pull that acts on an object.
Friction
A force that results when surfaces of objects rub against each other and opposes motion.
Static Friction
Friction that opposes the initiation of motion.
Kinetic Friction
Friction that opposes motion once the motion has already started.
Free Fall
The motion of an object when it is falling solely under the influence of gravity.
Inertia
The tendency of an object to resist changes in its velocity.
Newton’s First Law of Motion
An object in motion/rest will stay in motion/rest until it is acted upon by an outside force.
Newton’s Second Law of Motion
When an object is acted on by one or more unbalanced forces, the net force is equal to the mass of the object times the resulting action.
Newton’s Second Law of Motion
For every action, their is an equal and opposite reaction.
