3rd grade Science vocabulary answers

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Unit 1


Chapter 1

Lesson 1

  1. system:  a set of parts that interact with one another

Lesson 3

  1. deciduous:  loses leaves in fall and grows new ones in spring

  2. pollinate:  move pollen from the part of a flower that makes pollen to the part of the flower that makes seeds

  3. coniferous; a tree that produces seeds in cones

Lesson 4

  1. seed leaf;  part of a seed that has stored food

  2. germinate;  begins to grow

  3. seedling: a new, small plant that grows from a seed

Lesson 5

  1. fossil:  remains or mark of a living thing from long ago

  2. extinct; no longer lives on Earth


Chapter 2

Lesson 1

  1. trait; a feature passed on to a living thing from its parents

  2. vertebrate: animal with a backbone

Lesson 2

  1. larva: stage in an insect's life after it hatches from the egg

  2. pupa: stage in an insect's life between larva and adult

Lesson 3

  1. adaptation: trait that helps a living thing survive in its environment

  2. inherited; passed on from parent to offspring

  3. migrate: to move to another place to find better climate, food, or a mate

  4. hibernate: to spend winter resting; body systems slow down in order to save energy


Chapter 3

Lesson 1

  1. environment: everything that surrounds a living thing

  2. ecosystem: all the living and nonliving things that interact with each other in a given area

  3. population: all the living things of the same king that live in the same place a the same time

  4. community: populations that live together in the same place

Lesson 2

  1. grassland: land ecosystem that has many grasses and few trees

  2. dessert: an ecosystem that gets less than 25 cm of rainfall a year

  3. tundra: land ecosystem that is cold and dry

Lesson 4

  1. wetland: low land ecosystem that is covered by water at least part of the time during the year; marshes and swamps are wetlands


Chapter 4

Lesson 2

  1. producer: living things that make their own food

  2. consumer:  living things that eat food

  3. herbivore: living things that eat only plants

  4. carnivore: a living thing that hunts other animals for food

  5. omnivore: living things that eat plants and other animals for food

  6. prey: any animal that is hunted by others for food

  7. predator: a consumer that hunts other animals for food

Lesson 3

  1. competition: struggle that happens when two or more living things needs the same resource

Lesson 4

  1. decomposer: a living thing that breaks down waste and things that have died

  2. decay: to break down, or rot

Lesson 6

  1. germs: small living things that include bacteria and viruses, many of which can cause illness

  2. disease: the name we give an illness

Unit B


Chapter 5

Lesson 1

  1. water vapor: water in the form of an invisible gas in the air

  2. groundwater: water that has slowly made its way through soil and then collects in spaces between underground rock; it is brought to the surface by digging wells

  3. wetland: low land ecosystem that is covered by water at least part of the time during the year; marshes and swamps are wetlands

Lesson 2

  1. evaporation: the changing of a liquid to a gas

  2. condensation: changing of a gas into a liquid

  3. water cycle: the movement of water from Earth's surface into the air and back again

  4. precipitation: water that falls to Earth as rain, hail, sleet, or snow


Chapter 6

Lesson 1

  1. weather: what it is like outside including temperature, wind, clouds, and precipitation

  2. atmosphere: the blanket of air and gases that surround the Earth

Lesson 2

  1. hurricane: a huge, strong storm that forms over the ocean

  2. tornado: a rotating column of air that touches the ground and causes damage with its high winds

  3. blizzard: a winter storm with very low temperatures, strong winds, heavy snowfall, and blowing snow.


Chapter 7

Lesson 1

  1. rock: natural, solid, nonliving material made of more or more minerals

  2. mineral: natural material that forms from nonliving matter

  3. igneous rock: rock that forms when melted earth materials cool and harden

  4. sedimentary rock: rock that forms when small pieces of earth materials collect and become bound

  5. metamorphic rock: rock that forms when existing rock is changed by heat and pressure

Lesson 3

  1. soil; the part of Earth's surface consisting of humus and weathered rock in which plants grow

  2. decay: to break down or rot

  3. nutrient: thing plants need in order to grow

  4. loam: soil that contains a mixture of sand, silt, and clay


Chapter 8

Lesson 1

  1. crust: the outermost layer of Earth

  2. mantle: the middle layer of Earth

  3. core: the innermost layer of Earth

  4. landform: a natural feature on the surface of Earth's crust

Lesson 2

  1. magma: hot, molten rock that forms deep underground

  2. lava: hot, molten rock on Earth's surface

Lesson 3

  1. weathering; any process that changes rocks by breaking them into smaller pieces

  2. erosion: the movement of weathered material;

Chapter 9

Lesson 1

  1. natural resource: natural materials, such as soil, wood, water, air, oil, or minerals, that living things need

  2. renewable resource: resource that is endless like sunlight, or that is naturally replaced in a fairly short time, such as trees

  3. nonrenewable resource: resource that cannot be replace once it is used up

Lesson 2

  1. conservation:  wise use of natural resources

Lesson 3

  1. recycle:  treat or process something so it can be used again

Unit C


Chapter 10

Lesson 1

  1. matter: anything that takes up space and has mass

  2. property: something about matter that you can observe with one of more of your senses

  3. element: matter that has only one kind of atom

  4. atom: one of the tiny particles that make up all of matter

  5. periodic table: an arrangement of elements based on their properties

Lesson 2

  1. mass: amount of matter

  2. volume: amount of space matter takes up

  3. density: measure of the amount of matter in a certain amount of space

  4. buoyancy: force exerted on an object that is immersed in a gas or liquid that tends to make it float


Chapter 11

Lesson 1

  1. physical change; a change that makes matter look different without becoming a new substance

  2. states of matter: the forms of matter---solid, liquid, and gas

Lesson 2

  1. mixture: two or more kinds of matter that are placed together but can be easily separated

  2. solution: a mixture in which one or more substances dissolves in another

Lesson 3

  1. chemical change: a change that causes one kind of matter to become a different kind of matter


Chapter 12

Lesson 1

  1. position: the location of an object

  2. motion: a change in position of an object

  3. relative position: a change in an object's position compared to another object

  4. speed: the rate at which an object changes position

Lesson 2

  1. force: a push or a pull

  2. friction: a contact force that opposes the motion of an object

  3. gravity: a non-contact force that pulls objects toward each other

  4. magnetism: a non-contact force that pulls objects containing iron

Lesson 3

  1. work: what happens when a force moves an object over a distance


Chapter 13

Lesson 1

  1. potential energy: the energy something has because of it position

  2. kinetic energy: energy of motion

Lesson 3

  1. thermal energy: the total kinetic energy of all the particles that make up matter

Lesson 4

  1.  reflects: to bounce off of

  2. refract: to bend

  3. absorbs: to take in

Lesson 5

  1. electric charge: tiny amount of energy in the particles of matter

  2. electric current: the movement of an electric charge from one place to another

  3. electric circuit: the path that a controlled electric current flows through

Chapter 14

Lesson 1

  1. vibration: a very quick back-and-forth movement

  2. pitch; how high or low a sound is

Lesson 2

  1. compression waves: wave that has spaces where particles are squeezed together and spaces where particles are spread apart

Unit D


Chapter 15

Lesson 1

  1. star; a massive ball of hot gases that produces its own light

  2. axis: an imaginary line around which Earth spins

  3. rotation: one complete spin on an axis

Lesson 2

  1. revolution: one complete trip around the Sun

Lesson 3

  1.  phase: each different way the moon looks

Lesson 4

  1. telescope: a tool that gathers lots of light and magnifies objects that are far away an makes faint stars easier to see

  2. constellation: a group of stars that make a pattern


Chapter 16

Lesson 1

  1. planet: a large, ball-shaped body of matter that revolves, or travels, around any star

  2. solar system: the Sun, eight planets and their moons, dwarf planets, and other objects that revolve around the Sun

  3. orbit: the path of any object in space that revolves around another object in space

  4. asteroid: a small chunk of rock that orbits around the Sun

Chapter 17

Lesson 1

  1. tool: an object used to do work

  2. technology: the use of science knowledge to invent tools and new ways of doing things

  3. invention: something that has been made for the first time

Lesson 2

  1. computer: tool which stores, processes, and gets electronic information