Science Ch 5 - Water, Air, and Weather Flashcards
How much of the earth’s surface is covered with water?
three quarters
What are clouds made of?
water and air
Which kind of cloud is large and puffy?
cumulus
Which kind of cloud is light and feathery?
cirrus
Which kind of cloud looks like a blanket?
stratus
Which kind of cloud sometimes forms thunderheads?
cumulus
Which kind of cloud is called fog when it is very close to earth?
stratus
Which kind of cloud is often a sign of an approaching storm?
cirrus
Which kind of cloud is made of air and ice crystals?
cirrus
Which kind of cloud usually brings light rain or snow?
stratus
Which kind of cloud usually appears during fair weather?
cumulus
What percentage of your body is water?
65%
How much water does your body need to take in each day?
About 1.5 litres (Abbie) or 2 litres for an adult woman
What happens to your blood if you do not replace the water your body loses each day?
The blood becomes thicker and harder for the heart to pump.
What is matter?
anything that takes up space and has weight.
What is a molecule?
the smallest piece of a substance that still has all the qualities of that substance
What are the particles that make up a molecule called?
atoms
What happens to molecules of water during photosynthesis?
They are split into atoms of hydrogen and oxygen.
What happens to atoms of hydrogen and oxygen when your body uses food?
They are combined to form water.
In what three states does matter exist?
solid, liquid, and gas
Give an example of something in its solid, liquid, and gas states.
As a solid, water is ice; as a liquid, water; and as a gas, steam or water vapour.
Are ice, water, and steam different substances? Why or why not?
No. They are all different forms of the same substance.
Which state of matter has no shape and does not fill up a fixed amount of space?
a gas
Which state of matter has a definite shape and fills up a fixed amount of space?
a solid
Which state of matter has no shape of its own but fills up a fixed amount of space?
a liquid
List the states of matter according to the speeds of their molecules, from fastest to slowest.
gas, liquid, solid
Describe the action of molecules in a solid.
They vibrate very slowly.
What causes molecules to move more rapidly?
heat
What happens when the motion of the molecules in a solid or a liquid becomes stronger than the attraction of the molecules to each other?
The liquid becomes a gas and the solid becomes a liquid.
What is water’s melting point?
0 degrees Celsius (32 F)
What is water’s boiling point?
100 degrees Celsius (212 F)
What happens to most liquids when they become colder?
They contract.
What happens to water when it becomes colder?
It expands.
Why is this unique characteristic of water important?
It’s important because it causes ice to float rather than sink.
Why can objects heavier than water float in water?
surface tension
Which state of matter is represented in the picture shown?
a gas
Which state of matter is represented in the picture shown?
a liquid
Which state of matter is represented in the picture shown?
a solid
The ability to do work is…
energy
Work is done when an object has been…
moved
The force which draws things down toward the centre of the earth is…
gravity
Potential energy is what kind of energy?
stored energy
What supplies energy to water to make steam?
heat
True or false: In order for you to lift something, you must exert less force than gravity does on that object.
False. You must exert more force than gravity.
What is the layer of air surrounding the earth called?
the atmosphere
In which of the three states of matter does air exist naturally?
gas
Which of the gases in the air is the most plentiful?
nitrogen
Why is oxygen important for people, animals, and plants?
They need oxygen to breathe and to create energy.
Which gas do plants take from the air in order to make food?
carbon dioxide
What keeps the blanket of air around the earth?
gravity
Besides the atmosphere, where would you find air?
in the soil and in water
True or false: Air is matter.
true
True or false: Air weighs less than an equal amount of a solid or a liquid.
true
True or false: Although solids exert pressure, liquids and gases do not.
false
True or false: Air pressure at the top of a high mountain is equal to air pressure at sea level.
False. Air pressure decreases as you go higher into the atmosphere.
True or false: You do not feel air pressing down on you because pressure on all sides of you is equal.
true
How is air warmed?
by the earth
Why is it that not every place on earth receives the same amount of heat?
because the earth is tilted
How does uneven heating of the earth cause wind?
Uneven heating produces air that is cold and warm. As air continually heats and rises, cooler air continually flows in to take the place left by warmed air. This constant motion of the air is what causes wind.
List three helpful things the wind does.
- helps to even out the earth’s temperature;
- pollinates some plants
- lets us know of changing weather
List three harmful effects of the wind.
- spreads bushfires
- causes sandstorms
- causes erosion
Why would you not want to depend on wind power for all of the electricity you need?
The wind does not always blow at a constant speed.
True or false: The sun heats the air more than it does the land.
false
True or false: Some of the air that we breathe does not contain water vapour.
False. All air contains water vapour.
True or false: Water changes state as it travels from the earth to the air, over and over again.
true
True or false: Water can be in the air as a gas or a liquid but not as a solid.
false
True or false: There is always the same amount of water vapour in the air.
false
True or false: Cool air can hold more water vapour than warm air.
false
True or false: The process by which water becomes water vapour is called evaporation.
true
True or false: Heat from the sun causes evaporation.
true
True or false: Water evaporates more quickly on cool days than on hot days.
false
What kind of water is always in the air?
water vapour
Is warm, moist air lighter or heavier than cool air?
lighter
As it rises away from the earth’s surface, warm air begins to…
cool
Cool air cannot hold as much of this as warm air can.
water vapour
When water vapour in the air cools and turns into tiny droplets of liquid water, what takes place?
condensation
Water in the air condenses on tiny pieces of what
dust in the air
Four kinds of precipitation are…
rain, sleet, snow, hailstones
Water vapour that condenses on the grass at night is called…
dew
Tiny crystals of ice that are made of frozen water vapour are…
frost
What do we call rain that freezes into small, hard balls of ice?
sleet
What are snowflakes made of?
frozen water vapour
How many sides of points do snowflakes have?
six
Why must you melt ten inches of snow to get one inch of water?
There is trapped air in the snowflakes.
Explain how hail is formed.
Raindrops fall through very cold air and are frozen. The frozen raindrop is then blown back high into the cloud by a gust of wind. The frozen raindrop then falls through the cold air again, and a new layer of ice is added. This continues until the hailstone becomes too heavy to be blown back up into the cloud.
