General Science Proficiency Pointers and Fundamentals

Practice flashcards covering general science pointers, scientific methods, measurement systems, states of matter, changes in matter, machines, density, weather, and the water cycle.

Risks

Hazards or negative effects that lead to loss or injury, such as pesticides contributing to water pollution.

Phenomenon

A thing observed by the senses; a scientifically tested observation of this is called a fact.

Scientific Method

The logical method used by scientists to acquire knowledge that is used to explain different phenomena in nature.

Hypothesis

An "educated guess" made based on information or data gathered during the scientific method.

Controlled Experiment

An experiment involving the manipulation of one of the conditions or factors that may affect the result.

Trials

The number of times an experiment is repeated.

Controls

The factors that are kept constant throughout the experiment.

Variables

The factors that change during the experiment.

Independent or Experimental Variables

The specific factors that are changed during an experiment.

Dependent Variables

Factors that change as a result of changes in the independent variable.

Measurement

The process of comparing a quantity with a chosen standard.

International System (SI)

The system of units agreed upon by scientists and legally enforced worldwide, consisting of seven basic quantities.

SI Unit of Length

Meters

SI Unit of Mass

Kilograms

SI Unit of Time

Seconds

SI Unit of Electric current

Amperes

SI Unit of Temperature

Kelvin

SI Unit of Amount of substance

Moles

SI Unit of Luminous intensity

Candelas

Accuracy

The degree of closeness of measurements of a quantity to its actual (true) value.

Precision

The degree to which measurements under unchanged conditions show the same results.

Matter

Anything that occupies space and possesses the attributes of gravity and inertia.

Solid

A state of matter characterized by resistance to any change in shape due to strong attraction between molecules.

Liquid

A state of matter that does not resist forces that change its shape because molecules are free to move with respect to each other.

Gas

A state of matter where molecules are widely dispersed and freely move, offering no resistance to change of shape.

Plasma

The fourth state of matter consisting of an overall charge-neutral mix of electrons, ions, and neutral atoms.

Melting Point/Freezing Point

The temperature at which any given substance changes from solid to liquid and vice versa.

Boiling Point

The temperature at which a substance changes from liquid to gas and vice versa; it depends on atmospheric pressure.

Physical change

A change in matter that involves no chemical reaction, where the composition of molecules remains unchanged.

Sublimation

The physical change of state from a solid directly to a gas.

Chemical change

A change where the chemical composition of each molecule shifts, resulting in new substances with new properties, such as the production of iron oxide (rust).

Machines

Devices that can multiply force, multiply speed or distance, change force direction, transfer energy, or transform energy.

Simple machines

Mechanical devices with only one or two parts, classified into: inclined plane, lever, screw, wheel and axle, pulley, and wedge.

Compound/Complex machines

Devices that make use of two or more simple machines.

Density

The mass of the material divided by its volume, represented by the formula $P = \frac{\text{mass}}{\text{volume}}$.

Climate

The long-term effect of the sun's radiation on the rotating earth's surface and atmosphere; weather averaged over a long period of time.

Weather

The state of the atmosphere at a particular time and place, determined by elements like temperature, humidity, and precipitation.

Humidity

A measure of the amount of water vapor in the air.

Relative humidity

The amount of vapor in the air divided by the air's vapor-holding capacity at that temperature.

Hygrometer and Psychrometer

Instruments used in measuring atmospheric humidity.

Precipitation

Drops and crystals in clouds that grow large enough to fall to the ground, including rain, snow, hail, and sleet.

Rain gauge

An instrument used to measure precipitation.

Wind

The horizontal movement of air, named for the direction from which it comes.

Anemometer

An instrument used to measure wind speed.

Clouds

Excess water vapor in the air that condenses into liquid droplets or ice crystals.

Cumulus clouds

Fluffy clouds formed from rising masses of air called thermals, often having a flat base.

Cirrus clouds

Fibrous clouds consisting of trails of falling ice crystals twisted by winds, usually forming high in the troposphere.

Stratus clouds

Clouds that form when an entire layer of air cools or ascends obliquely, often extending for hundreds of miles.

Pressure

The force of the air on a given surface divided by the area of that surface.

Barometer

The most common instrument used to measure air pressure.

Hydrologic Cycle (Water Cycle)

The series of movements of water above, on, and below the earth's surface, consisting of storage, evaporation, precipitation, and run-off.