Year 8 Science Study Notes

Energy

The ability to do work and cause changes.

Law of Conservation of Energy

Energy cannot be created or destroyed, only transformed from one form to another.

Kinetic energy

The energy of movement.

Potential energy

Stored energy that has the potential to do work when released.

Thermal/Heat energy

Energy created by a rise in temperature that causes atoms and molecules to move faster.

Light (radiant) energy

Energy that can move through empty space and produces photons.

Mechanical energy

Energy that moves objects from one place to another.

Sound energy

The energy that the air has when it is vibrating.

Electrical energy

Energy that is caused by the movement of electrons within an atom.

Gravitational energy

Potential energy due to an object's higher position compared to a lower position.

Chemical energy

Stored energy in the bonds that connect atoms with other atoms/molecules.

Nuclear energy

Energy that comes from the nucleus of atoms.

Elastic energy

Energy that is stored in elastic materials.

Energy transfer

The movement of energy from one location to another.

Energy transformation

When energy changes from one form to another.

Energy efficiency

The measure of how good a device is at changing energy from one form to another.

Cell

Stores chemical energy and transfers it to electrical energy when a circuit is connected.

Electrical current

The flow of microscopic particles called electrons through wires and components.

Electric circuit

An electrical device that provides a path for electrical currents to flow.

Simple circuit

A circuit with a cell, lamp, and a switch connected together with metal wires.

Series circuit

Components are connected end to end, one after the other.

Parallel circuit

Components are connected side by side, giving the current a choice of routes.

Measuring current

Electric current is measured in amps (A) using an ammeter connected in series.

Measuring voltage

Voltage is measured in volts (V) using a voltmeter connected across the components.

Human Digestive System

The system responsible for breaking down food and absorbing nutrients.

Carbohydrates

A type of nutrient that provides long-term energy.

Fat

A type of nutrient that protects organs and serves as a long-term energy store.

Protein

A type of nutrient used for muscle building, enzyme production, and other functions.

Sugars

A type of nutrient that provides fast energy.

Mouth

Part of the digestive system where mechanical and chemical breakdown of food begins.

Oesophagus

Tube that carries food from the throat to the stomach.

Stomach

Organ that chemically breaks down food into tiny pieces and mixes it with digestive enzymes and acid.

Liver

Organ that produces bile to help dissolve fat and processes nutrients in the blood.

Gallbladder

Organ that stores bile from the liver and delivers it when food is digested.

Pancreas

Organ that produces compounds to digest fats and proteins and regulates blood sugar.

Small intestine

Long tube where enzymes and bile complete digestion and nutrients are absorbed into the bloodstream.

Large intestine

Tube that absorbs water and minerals from waste matter.

Rectum

Stores waste before egestion.

Anus

Muscular ring that controls egestion.

Circulatory System

The system in the body responsible for transporting blood, consisting of blood, blood vessels, and the heart.

Blood

The fluid in the body that carries oxygen, nutrients, and waste products.

Blood vessels

Tubes in the body through which blood travels, including arteries, veins, and capillaries.

Heart

The organ that pumps blood throughout the body.

Plasma

The liquid part of the blood.

White blood cells

Cells in the blood that fight and kill germs.

Platelets

Cells in the blood that help with blood clotting.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Capillaries

Tiny blood vessels that connect arteries to veins.

Respiratory System

The system in the body responsible for exchanging gases with the environment, including the lungs and airways.

Cellular respiration

The process by which cells convert glucose and oxygen into energy.

Breathing

The movement of air into and out of the lungs.

Trachea

The tube that connects the throat and bronchi.

Cilia

Tiny hairs in the airways that help clean the air.

Diaphragm

A large muscle that controls the size of the chest cavity during breathing.

Lungs

The organs in the respiratory system where gas exchange takes place.

Alveoli

Clusters of air sacs in the lungs where oxygen and carbon dioxide are exchanged.

Excretion

The removal of waste products from the body.

Urinary system

The system in the body responsible for producing and excreting urine, including the kidneys, ureters, bladder, and urethra.

Kidney

The organ in the urinary system that filters waste products from the blood and produces urine.

Ureters

Tubes that transport urine from the kidneys to the bladder.

Bladder

The organ that stores urine.

Urethra

The tube that eliminates urine from the body.

Skeleton

The collection of bones in the body that provides support and protection.

Compact bones

Dense and heavy bones that give strength.

Spongy bones

Bones filled with bone marrow and involved in blood cell production.

Joints

The place where two bones come together, allowing movement.

Muscular system

The system in the body responsible for movement, consisting of muscles and tendons.

Tendons

Tissues that attach muscles to bones and hold muscles together/in position.

Crust

Outermost layer of Earth, relatively thin (5 to 70 km thick), solid layer.

Mantle

Primarily made of solid rock, but has semi-liquid properties due to high temperatures and pressure.

Upper Mantle

Partially molten and responsible for moving tectonic plates through convection currents.

Lower Mantle

Solid rock.

Outer Core

Primarily composed of liquid iron and nickel.

Inner Core

Innermost layer of the Earth (the core), solid due to immense pressure, composed of iron and nickel.

Lithosphere

The solid, outer part of Earth, includes the crust and upper mantle.

Asthenosphere

The plastic layer of the mantle that behaves as a ‘plastic solid’ - rocks flow slowly, similar to melted plastic (molten rocks).

Magma

Semi-liquid rock that forms beneath the Earth’s surface.

Lava

Magma that pushed other rocks through faults and cracks, reaching the surfacing and becoming lava.

Convection currents

The way heat moves through a fluid, causing the movement of tectonic plates.

Igneous Rocks

Formed from the cooling and solidification of molten rock material, either magma (found beneath Earth's surface) or lava (found on Earth's surface).

Intrusive Rocks

Formed below Earth's surface with magma and cools slowly, having larger mineral crystals.

Extrusive Rocks

Form on Earth's surface with lava and cools rapidly, having smaller mineral crystals.

Sedimentary Rocks

Formed from the accumulation and compression of sediment, including particles of minerals and organic material.

Clastic Rocks

Formed from the compaction of minerals and rock.

Chemical Rocks

Formed by the precipitation of dissolved materials.

Organic Rocks

Composed of organic material.

Metamorphic Rocks

Formed from the transformation of other rocks.

Weathering

The breaking down of rocks by natural processes.

Physical Weathering Factors

Temperature changes, action of water and ice, crystallization of salt, wind, living plants.

Chemical Weathering

Involves water, chemicals, and air reacting with the rocks.

Erosion

The removal of soil and rock fragments by wind and water from an area.

Glacial Erosion

Carries away particles of rocks.

Rock Cycle

The continuous process of rocks changing from one type to another over time.

Relative Dating

A method of estimating the age of rocks by comparing the ages of different things.

Ores

Rocks containing naturally occurring minerals that are valuable.

Properties of Minerals

Hardness, luster, color, streak.

Fossil

The prehistoric remains of a plant or animal embedded into rock and preserved.

Fossil Formation

The process of how fossils are formed.