Shimane Public High School Entrance Examination - Science flashcards

38 cards. Read the term and the definition here. The deck at the top of this page is optional.

Speed

The distance an object travels per unit time, commonly expressed in metres per second or kilometres per hour; it describes how quickly position changes and is a scalar quantity.

Uniform linear motion

Motion in which an object moves along a straight line at a constant speed, so it covers equal distances in equal time intervals and its velocity does not change.

Inertia

The tendency of an object to resist changes in its state of motion; an object at rest stays at rest, and a moving object continues at constant velocity unless a net force acts.

Work

The transfer of energy when a force moves an object through a distance in the direction of the force; measured in joules and calculated as force times distance.

Mechanical energy

The sum of an object's kinetic energy and gravitational potential energy in a mechanical system; it can change form but is conserved when only gravity does work.

Frequency

The number of complete oscillations per unit time, measured in hertz; it relates to perceived pitch for simple sounds and to monochromatic light frequency.

Ohm's law

The relationship stating that the current through a metallic conductor is proportional to the potential difference across it, provided temperature stays constant; expressed as V = IR.

Electromagnetic induction

The production of an electromotive force when magnetic flux linking a circuit changes; current can flow when an appropriate conducting circuit is closed.

Heating effect of current

The conversion of electrical energy into thermal energy when current flows through a resistance; the heating effect increases with current, resistance, and time.

Atom

A particle identifying an element by its proton count, consisting of a nucleus and electrons when neutral; not every atom contains a neutron.

Molecule

A group of two or more atoms chemically bonded together, forming the smallest unit of a substance that can exist independently while keeping its chemical properties.

Ion

An atom or group of atoms that has gained or lost one or more electrons, giving it a positive or negative electric charge and allowing it to conduct electricity in solution.

Chemical equation

A symbolic representation of a chemical reaction using element symbols and formulas, with reactants on the left and products on the right, balanced to show conservation of atoms.

Law of conservation of mass

The principle that the total mass of the reactants equals the total mass of the products in a closed chemical reaction, because atoms are rearranged but not created or destroyed.

Chemical combination

A reaction in which two or more substances join chemically to form a single new substance, such as iron combining with sulfur when heated.

Decomposition

A chemical reaction in which a single compound breaks down into two or more simpler substances, often requiring heat, electricity, or light.

Oxidation

A reaction in which a substance gains oxygen or loses electrons; in everyday terms it includes burning, rusting, and the tarnishing of metals.

Reduction

A chemical reaction in which a substance loses oxygen or gains electrons; it often occurs together with oxidation in processes such as extracting metals from ores.

Neutralization

An acid-base reaction that can form water and a salt in the aqueous acid-hydroxide model; the final pH also depends on quantities and reactant strengths.

Solubility

The maximum mass of a solute that can dissolve in a fixed amount of solvent at a given temperature, often expressed in grams per 100 grams of water.

Recrystallization

A purification method in which a substance is dissolved in a hot solvent and then cooled so that pure crystals form while impurities remain dissolved or are filtered out.

Cell

The basic structural and functional unit of living things; it contains genetic material and is surrounded by a membrane that controls what enters and leaves.

Cell division

The process by which a parent cell splits to form two or more daughter cells, allowing growth, repair, and reproduction in organisms.

Meiosis

A division process that reduces chromosome number, typically producing haploid cells from a diploid cell; its role in forming gametes depends on the organism life cycle.

Heredity

The passing of genetic information from parents to offspring through genes, which determines inherited traits such as eye colour or plant height.

Photosynthesis

The process by which green plants and some other organisms use sunlight, water, and carbon dioxide to produce glucose and oxygen inside chloroplasts.

Respiration

Cellular processes releasing usable energy from substrates; aerobic respiration uses oxygen, while some energy-releasing pathways operate without molecular oxygen.

Food chain

A sequence showing how energy and nutrients pass from one organism to another through feeding relationships, starting with a producer and ending with a top predator.

Ecosystem

A community of living organisms interacting with each other and with their non-living environment, including factors such as sunlight, water, soil, and temperature.

Reflex

A rapid automatic response to a stimulus that does not require conscious thought, mediated by a reflex arc through the spinal cord or brain.

Earthquake

A sudden shaking of the ground caused by the release of energy when rocks along a fault break and slip, producing seismic waves.

Focus

The point inside the Earth where an earthquake starts and energy is released; the point directly above it on the surface is the epicentre.

Magma

Molten rock beneath the Earth's surface, containing dissolved gases and minerals; it becomes lava when it erupts onto the surface.

Sedimentary rock

Rock formed from layers of sediment that are compacted and cemented over time, often preserving fossils and showing stratification.

Strata

Layers of sedimentary rock or soil arranged one above another; younger layers are usually on top unless the ground has been disturbed.

Front

The boundary between two air masses with different temperatures and densities; it often brings changes in weather such as rain or strong winds.

Revolution

Orbital motion of one body around another; Earth’s revolution together with its axial tilt produces the main seasonal illumination pattern.

Rotation

The spinning of a celestial body around its own axis, such as Earth's daily rotation, which causes day and night.