4TH GRADE SCIENCE CUMULATIVE CRCT STUDY GUIDE
Science is cool, fun, exciting, interesting, and EASY!!
“Cycles and Patterns in Space”
Planets
Mercury, Venus, Earth and Mars are the inner planets. They are the planets closest to the Sun; so they get more
heat and light from the Sun.
Jupiter, Saturn, Uranus, and Neptune are the outer planets. They are farther away from the Sun; so they are cold
and dark. The outer planets are made of gas and have many moons. Jupiter, Saturn, Uranus, and Neptune are the
4 gas giants. A gas giant is a very large planet made up of gases.
Space probes help Scientist study things in space. A space probe is a craft that help scientists explore outer
space.
My (Mercury) Very (Venus) Educated (Earth) Mother (Mars) Just (Jupiter) Served (Saturn)
Up (Uranus) Nachos (Neptune)
Earth- only planet we know that has living things.
Mars- has many craters and mountains.
Jupiter-is largest planet.
Saturn- has rings and is made of dust, ice, and rocks.
Uranus- spins or turns on its side.
Neptune- is blue.
The Sun
Stars are big balls of hot gas that gives off light. The Sun is a star. It gives us light and heat. The stars make
patterns called constellations. There are 88 constellations. As Earth rotates this makes the constellations appear
to move but they don’t.
What causes day and night? / What causes Earth’s year?
Planets move. Earth spin like a top or rotates on its axis as it orbits the Sun. Earth’s spin or rotation takes 24
hours and causes day and night. An axis is an imaginary or made up line through the middle of an object.
Earth’s axis goes through the North and South Poles. Earth also orbits the Sun. To orbit is to move in a path
around an object. Earth’s orbit around the Sun takes approximately 365 days or 1 year.
What Causes Earth’s Seasons to change?
You have learned that Earth orbits and rotates. Earth also revolves the Sun; which is like orbiting except with a
tilt. The tilt causes the Sun’s light to shine on Earth in different ways causing different seasons. Earth’s tilt
causes the change in seasons.
The equator is a made-up line that circles Earth. It divides Earth into two halves (the Northern hemisphere and
the Southern hemisphere). You live in the Northern hemisphere (the half of the Earth closer to the Northern
Pole. In June, the Northern Hemisphere tilts toward the Sun. It gets a lot of light, so it is summer here. In
December the Northern Hemisphere tilts away from the Sun. It does not get a lot of light, so it is winter here.
When it is summer for the Northern part of the Earth, the Southern part is in winter.
What Are the Phases of the Moon?
The Moon is a ball-shaped object made of rock. The Moon does not make its own light. It reflects, or bounces back
the Sun’s light. The reflected like makes the Moon’s near side look bright (the side near the Sun). The other side is dark,
so you cannot see it. The Moon revolves or orbits the Sun; which takes about 29 and ½ days to happen.
Phase 1- New Moon (Near side does not get any light).
Waxing Moon- In the waxing phases the Earth’s near side is receiving light.
Phase 2- Waxing Crescent Moon (Only thin crescent gets sunlight).
Phase 3- First Quarter Waxing Moon (Half of the near side gets light).
Phase 4- Waxing Gibbous Moon (Three-quarters of the Moon’s near side gets sunlight).
Phase 5- Full Moon (The whole near side gets light.)
Waning Moon- In the waning phases the Earth’s near side is beginning to get dark.
Phase 6- Waning Gibbous Moon (Most of the light on Earth’s near side decreases).
Phase 7- Third Quarter Waning Moon (Half of the near side is dark).
Phases 8-Waning Crescent Moon. (Some of the light on Earth’s near side decreases).
New Moon (The entire Moon is dark again. The cycle will start over. It takes the Moon approximately 29 and ½ days to
revolve or orbit the Sun.
“Weather”
What is Air?
Air is made up of gas. It has no color or smell. Air is made up of nitrogen, oxygen, and gases. Animals
and people need oxygen from the air and planets. People breathe out carbon dioxide which plants need to
make food and grow.
Earth’s atmosphere is a layer of gases that protects Earth like a blanket. It traps in some heat and lets
out some keeping Earth from getting too hot or too cold. The weight of air as presses down on Earth is
air pressure.
What are the forms or states of water?
Water can be a liquid, solid, or gas and can go back and forth from one form to the other. If water is
turned into ice and then the ice is allowed to melt, the amount of water is the same as it was before
freezing.
What is the water cycle?
During the water cycle water moves into the air as a gas (evaporation) and goes into the sky to form
clouds of condensation, the water condenses or cools (condensation), and falls back to Earth’s surface as
precipitation. Some precipitation flows down into the ground. This water is called groundwater.
What are the types of clouds and the weather they bring?
Stratus clouds are low-level clouds that form in layers and usually bring rain.
Cumulus clouds are fluffy and are flat at the bottom. They usually mean fair weather.
Cirrus clouds are thin clouds that look like feathers. They are made of ice crystals.
Cumulonimbus clouds bring thunderstorms.
Forms of Precipitation
Rain is falling drops of liquid water.
Sleet forms when rain freezes as it falls.
Snow is falling ice crystals.
Hail form when drops of rain freeze and strong winds carry them higher into a cloud. As they fall more
ice forms on them.
Weather Instruments
A rain gauge collects and measures the amount of precipitation that has fallen in an area.
A thermometer measures the temperature of the air.
An anemometer measures the speed of the wind.
A barometer measures air pressure.
Weather Conditions
Weather is the conditions of the atmosphere at a certain place and time.
An air mass is a large body of air with the same temperature, air pressure, and moisture (water in the
air). Warm air masses are warm and moist. Cold are masses are cold and dry. The place where two air
masses meet is called a front.
A meteorologist is a scientist that studies, analyzes, and predicts weather.
Climate
Climate is the usual weather conditions in an area over time. Earth is divided into three climate zones.
Climate Zones
A tropical climate is hot and rainy. A polar climate has very cold temperatures year round. A temperate
climate often has warm, dry summers and cold, wet winters.
“All about Light”
What is Light?
Light is a form of energy that you can see. It moves in waves. Most objects do not give off their own light. You can see
them because light from another source bounces off them.
How can you see an object? Light waves hit the object and bounces off it.
Example:
If you look at a toy light from a light source hits your eyes. That light bounces from your eyes to the toy and you see the
toy. Cool Right!
Light and Matter
You can see light through things that are transparent. A transparent object lets light pass through it. (Examples: A
glass, a window, a clear bottle.)
You can see some light through things that are translucent. A translucent objet lets some light pass through it.
(Examples: Frosted glass)
You cannot see any light through things that are opaque. An opaque object does not let light pass through it. (Examples:
Walls, wood, or rocks)
Shadows
A shadow is made where your body blocks the light.
How is light reflected?
Light waves reflect or bounce off most objects. This is why you see yourself in a mirror. Sometimes light waves may
change when they hit some things like when they move from air to water. Light waves refract or bend when they move
from air to water. A lens is an object that bends light.
What is color?
White light is made up of all the colors of the rainbow. You can see many colors when light shines through a prism. A
prism is a piece of glass or other transparent object. It is shaped like a triangle. It breaks white light into many colors.
How Are Sounds Made?
Sound is a kind of energy that we can hear. Sound moves in waves. Sound is made when objects vibrate, or move
back and forth quickly. Sound can travel through solid, liquid, and gas. Sound travels faster through a solid and slowest
through a gas. Sound cannot travel through empty space it has to have a medium (solid, liquid, or gas).
Pitch is how high or low a sound is. Pitch is caused by the frequency (number of waves that pass in a given time). Highfrequency waves make the pitch high. Low-frequency waves make the pitch low.
Volume is how loud or soft a sound is. Volume depends on the amplitude (energy) of a sound wave. A wave with large
amplitude (lot of energy) will have a loud volume. A wave with small amplitude (little energy) will have a soft sound.
“Ecology”
How does energy flow in a food web?
A food chain shows the path of energy in an ecosystem. A food chain begins with a producer (make their own foodplants). Photosynthesis is the process by which plants use the sun to make food.
Consumers are part of a food chain.
An herbivore eats only plants. An omnivore eats plants and animals. A carnivore eats only animals.
A food web shows more than one food chain that overlaps.
A scavenger is a consumer that eats the remains or wastes of other animals. Vultures are scavengers.
Predators hunt and kill other animals. A prey is the animal that is hunted or eaten by another animal.
A decomposer is a living thing that breaks down the remains of dead organisms. Bacteria and fungi help break down some
living things.
“Adaptation and Extinction”
How are organisms adapted to survive?
Physical features can help animals survive.
An adaptation can be a physical feature or a behavior that helps a plant or animal survive.
Camouflage is the coloring or marking of an animal that helps it look like what is around them.
Mimicry is an adaptation where an animal looks like another animal or a plant.
Behaviors can help animals survive.
Some animals hibernate or go into deep sleep during which they use very little energy.
Some animals migrate or move to another region to find food or warmer temperatures.
Why do scientists study fossils?
Scientists study fossils to learn about plants and animals that existed a long time ago. A fossil is the preserved remains of
an organism that lived long ago.