SCIENCE GR 9 EXAM REVIEW

What is the periodic table?

A chart organizing chemical elements by atomic number and properties.

What are acids and bases?

Acids donate protons; bases accept protons.

What is gravity?

The force that pulls objects together based on mass.

Describe cellular respiration.

The process cells use to turn glucose and oxygen into energy.

What is the difference between a meteor and a meteorite?

A meteor is a streak of light; a meteorite is a piece that lands on Earth.

What is energy transformation?

Changing energy from one form to another.

What is an ecosystem?

A community of living organisms and their environment.

What is the greenhouse effect?

Heating of the Earth due to gases trapping heat.

What are tectonic plates?

Huge pieces of Earth's surface that move and can cause earthquakes.

What is the role of producers in an ecosystem?

Organisms that make food for themselves and others.

What is an atom?

The smallest part of an element that keeps its properties.

Define the law of conservation of mass.

Mass is neither created nor destroyed in reactions.

What is a compound?

A substance made of two or more elements bonded together.

Explain the Big Bang Theory.

The theory that the universe started very hot and has expanded.

What is Newton's First Law of Motion?

An object stays still or keeps moving unless acted on.

Define photosynthesis.

The process plants use to turn sunlight into food.

What are the three states of matter?

Solid, liquid, gas.

What is biodiversity?

The variety of life in a habitat.

List the planets in our solar system in order from the sun.

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

What is potential energy?

Energy due to an object's position.

What is kinetic energy?

Energy an object has because it is moving.

What is a chemical reaction?

A process where substances change into new substances.

Describe the structure of DNA.

A double helix made of nucleotide bases.

What are the four types of macromolecules?

Carbohydrates, lipids, proteins, nucleic acids.

What is a food chain?

A sequence of organisms that eat one another.

What is a food web?

A complex network of food chains in an ecosystem.

What is an ion?

An atom or molecule with a charge due to lost or gained electrons.

Define an isotope.

Atoms of the same element with different numbers of neutrons.

What is a solute?

A substance that is dissolved in a solution.

What is a solvent?

The substance that dissolves the solute.

What is diffusion?

The movement of molecules from high to low concentration.

What is osmosis?

Water moving through a membrane from low to high solute concentration.

What is a hypothesis?

A testable prediction about relationships between variables.

What is a theory?

A well-supported explanation of a natural phenomenon.

What is a variable in an experiment?

A factor that can change and affect results.

What is qualitative data?

Descriptive information that can't be measured with numbers.

What is quantitative data?

Numerical information that can be measured.

What is evolution?

Change in species over time through natural selection.

Define natural selection.

Survival of the fittest; organisms best suited to their environment thrive.

What is the scientific method?

A process for investigation involving observation, hypothesis, and experimentation.

What is a biome?

A large area with specific climate and life forms.

What is climate?

Long-term weather conditions in a particular area.

What is habitat fragmentation?

The division of larger habitats into smaller, isolated pieces.

What is a renewable resource?

A resource that can be replenished naturally.

What is a non-renewable resource?

A resource that cannot be replaced within a human lifetime.

What is symmetry in nature?

A balanced arrangement of parts in organisms.

What are trophic levels?

The position of organisms in a food chain.

What is extinction?

The permanent loss of a species.

What is the function of chlorophyll?

Captures light for photosynthesis.

Define cellular organization.

Levels of organization in biological systems.

What is homeostasis?

Maintaining a stable internal environment.

What is biomass?

Total mass of living matter in an area.

What is bioaccumulation?

Build-up of substances in organisms over time.

What is biomagnification?

Increased concentration of toxins at higher food chain levels.

What is a population in ecology?

A group of the same species living together.

What is a community in ecology?

Different populations living together in an area.

What is a mixture?

A combination of substances that can be separated.

What is combustion?

Rapid reaction with oxygen producing heat and light.

What is stoichiometry?

Calculations based on chemical reactions.

What is the difference between a physical change and a chemical change?

A physical change does not alter chemical composition; a chemical change does.

What is a biogeochemical cycle?

Natural process recycling nutrients between living and non-living parts.

What is the importance of water as a solvent?

It dissolves more substances than any other liquid.

What is energy in the context of chemical reactions?

Capacity to do work during reactions.

What is the significance of the mole concept in chemistry?

Counting particles using Avogadro's number.

What is an oxidation-reduction (redox) reaction?

A reaction involving electron transfer.

What is density in relation to solutions?

Mass per unit volume of a solution.

What is the role of temperature in solubility?

Higher temperatures usually increase solubility for solids.

What is a precipitate?

A solid that forms from a solution during a reaction.

What is chromatography?

A technique to separate mixtures into components.

What is titration?

Determining concentration by adding a known solution.

What are polymers?

Large molecules made of repeating units.

What is Newton's Second Law of Motion?

Force equals mass times acceleration.

What is Newton's Third Law of Motion?

For every action, there is an equal and opposite reaction.

What is voltage?

The potential energy for electricity in a circuit.

What is the difference between series and parallel circuits?

Series has one path; parallel has multiple paths for current.

What is wavelength?

Distance between successive wave peaks.

What is frequency?

How often a repeating event occurs.

What is the electromagnetic spectrum?

All types of electromagnetic radiation arranged by wavelength.

What is sound?

Mechanical waves that travel through a medium.

What is refraction?

Bending of a wave as it enters a different medium.

What is reflection?

Bouncing back of a wave from a barrier.

What is inertia?

Resistance of an object to change in motion.

What is a simple machine?

A device that changes the direction or strength of a force.

What is the difference between scalar and vector quantities?

Scalars have only magnitude; vectors have both magnitude and direction.

What is a parallel circuit?

A circuit where components share the same voltage.

What is a series circuit?

A circuit with components connected one after another.

What is the formula for calculating total resistance in series circuits?

Total resistance is the sum of individual resistances.

What is the formula for calculating total resistance in parallel circuits?

Reciprocal of total resistance equals the sum of reciprocals of each resistance.

What happens to voltage in a series circuit?

Total voltage is divided across components.

What happens to voltage in a parallel circuit?

Voltage remains the same across all components.

What is the formula for calculating power in electrical circuits?

Power equals current times voltage.

What is the formula for total power in parallel circuits?

Total power equals the sum of individual powers.