4th Grade Science Vocabulary

Transcription

1 4th Grade Science Vocabulary hardness the number on the Moh s scale representing the hardness of a mineral luster the way a mineral reflects light mineral a naturally occurring substance, neither plant nor animal Moh s scale scale used to indicate the hardness of a mineral from 10 hardest to 1 softest scratch test a test used to determine the color of the streak of a mineral streak color the color of a mineral s streak when using a streak plate streak plate a plate used for testing a mineral s hardness igneous rock fire made rock formed from melted rock material metamorphic rock rock formed by heat and pressure sedimentary rock rock formed by bits or layers of rocks cemented together geologist a scientist that studies rocks and minerals geological region a distinct region of geological features geological formation rock unit distinguished from adjacent deposits by some common character, as composition, origin, type of fossil, etc. core the center layer of the Earth crust solid rock that makes up the Moon s and Earth s outermost layers inner core A sphere of solid material at the center of the Moon or Earth. lava the molten, fluid rock that issues from a volcano or volcanic vent magma molten material beneath or within the earth's crust, from which igneous rock is formed magma chamber an underground cavity containing molten rock, esp. below a volcano; also called a magma reservoir mantle the layer of rock lying below the crust erosion the wearing away of soil and rock particles by waves, wind, running water, or glaciers. See deposition

2 weathering to discolor, disintegrate, or affect injuriously, as by the effects of weather: These crumbling stones have been weathered by the centuries habitat the home of an organism dependence the state of relying on or needing someone or something for aid, support, or the like trait a characteristic of a living thing environment the air, water, minerals, organisms, and all other external factors surrounding and affecting a given organism at any time reptile a cold-blooded vertebrate that lives on land and has a backbone, an endoskeleton, and waterproof skin with scales or plates amphibians a cold-blooded vertebrate that spends part of its life in water and part of its life on land mammals a warm-blooded vertebrate with hair or fur; female mammals produce milk to feed their young fish any of various cold-blooded, aquatic vertebrates, having gills, commonly fins, and typically an elongated body covered with scales birds any warm-blooded vertebrate of the class Aves, having a body covered with feathers, forelimbs modified into wings, scaly legs, a beak, and no teeth, and bearing young in a hard-shelled egg invertebrates an animal without a backbone vertebrate an animal with a backbone adaptation a special trait that helps an organism survive warm-blooded said of an animal with a constant body temperature cold-blooded said of an animal that cannot control its body temperature exoskeleton a hard covering that protects an invertebrate s body endoskeleton an internal supporting structure mimicry when one organism imitates the traits of another camouflage an adaptation by which an animal can hide by blending in with its surroundings food chain the set of steps in which organisms get the food they need to survive

3 food web the pattern that shows how food chains are related arthropod an invertebrate with jointed legs and a body that is divided into sections cell the smallest unit of living matter classification the placement things that share properties together in groups fungi one-celled organisms that have cell walls but no nuclei inherited traits traits that are inborn, not learned kingdom the largest group into which an organism can be classified scales one of the thin, flat, horny plates forming the covering of certain animals, as snakes, lizards learned behavior behavior that is not inborn mollusk a soft-bodied invertebrate organism a living thing that carries out five basic life functions on its own protist any of the one-celled organisms that live in water. Some are plantlike and make their own food. Some are animal-like and are capable of motion carbon dioxide a colorless, odorless, incombustible gas formed during respiration community the living part of an ecosystem diversity the state or fact of being different; unlikeness ecosystem the living and nonliving things in an environment, and all their interactions endangered species a species at risk of extinction hibernation to spend the winter in close quarters in a dormant condition, as bears and certain other animals instinct a pattern of behavior that requires no thinking because it is programmed into an animal s brain metamorphosis a process of changes in form during an animal s development migration the act of movement from one region or climate to another niche the position of an organism in a community of plants and animals

4 oxygen a part of the air that is needed by most plants and animals to live population one type of organism living in an area variation a difference in structure or behavior from others of the same species or group pollution the adding of harmful substances to the water, air, or land carbohydrates class of organic compounds that form the supporting tissues of plants and are important food for animals and people digestion process by which food is converted into substances that can be absorbed by the body breakdown of foods into simpler chemical compounds nutrients nourishing; providing nourishment or nutriment small intestine the narrow, longer part of the intestines starch a white, tasteless, solid carbohydrate calorie unit of measurement of the amount of energy in food grain a small, hard seed, esp. the seed of a food plant such as wheat, corn, rye, oats, rice water a transparent, odorless, tasteless liquid, a compound of hydrogen and oxygen proteins considered as a food source supplying essential amino acids to the body combination foods a basic component of optimal nutrition because it allows the body to digest and utilize the nutrients in our foods to their full extent. components any smaller, self-contained part of a larger entity. Component may refer to electronic circuits. oils any substances typically liquid at ordinary temperatures, and not soluble in water: used for lubricating. fats any greasy substances formed of tissue of animals and also occurring in plants, that, when pure are colorless, odorless, and tasteless and are either solid or liquid, vitamins any of a group of organic substances essential to normal metabolism, found in minute amounts in natural foodstuffs weight the amount or quantity of heaviness or mass; amount a thing weighs. parallel circuit a circuit in which each object is connected to the cell separately series circuit a circuit in which the objects are connected in a single path.

5 lightning a discharge of static electricity from a thundercloud discharge the sudden movement of an electric charge from the object where it built up to another nearby object friction a force between surfaces that slows objects down or stops them from moving static electricity the buildup of an electric charge on a material calories the unit of measurement of chemical energy in food chemical energy the energy your body uses to walk, run, or lift things energy the ability to do work, either to make an object move or to change matter force any push or pull that makes an object start moving, stop moving, speed up, slow down, or change direction current electricity a moving electrical charge attract to draw to itself repel to force back magnetism the power to attract iron and steel as a magnet does magnetic pole 1. either of the poles of a magnet where the magnetic field is strongest 2. Either of two points on the surface of the earth near the North and South Poles, where the earth s magnetic field is the strongest magnetic field a region of magnetic force around a magnet magnetic force the force exerted between magnetic poles electric circuit a complete path through which electricity can flow open circuit a circuit which contains gaps or breaks so that it will not allow electricity to flow closed circuit a circuit which is complete and allows electricity to flow conductor a material through which heat or electricity flows easily insulator a material through which heat or electricity does not flow easily. resistor a material through which electricity has difficulty flowing switch a device that can open or close an electric circuit

6 electromagnet a temporary magnet created when current flows through wire wrapped in coils around an iron bar electromagnetism a temporary magnetic force created when current flows through wire wrapped in coils around an iron bar energy source materials such as coal, wood, gas, and oil that are used to generate electricity energy receiver a device used to receive the energy generated by various sources