Properties of Water - Science - Grade 9
Why is water less dense when it is in a frozen state?
ice molecules align in a regular lattice
What can the pH of water in nature indicate?
increasing pollution or some other environmental factor
What does it mean for water to have a high heat capacity?
it absorbs a lot of heat before it gets hot
When water freezes, what happens to its density?
it decreases
When water is heated, what happens to its density?
it decreases
Explain how to read a meniscus
read a meniscus as 66 milliliters
How much more acidic is a pH of 5 compared to a pH of 6?
ten times
What causes surface tension?
the cohesive force between liquid molecules
What is capillary action?
the movement of water within the spaces of porous materials
Why is water called a "universal solvent"?
water dissolves more substances than any other liquid
How does the surface tension of water compare to the surface tension of other liquids?
water has the greatest surface tension of any liquid
Explain how our kidneys filter water and how the universal solvent property is important in that provess
water washes through our kidneys and dissolves substances while taking them out of the body
Why is water being a universal solvent important to living things?
wherever water goes it takes along valuable chemicals, minerals and nutrients
What number on the pH scale is the most acidic? Which number is the most alkaline?
0 14
How much does the density of water decrease when it is in a frozen state?
9 percent
What 2 properties of water make capillary action possible?
It is possible because of cohesion and adhesion
Why is water called a universal solvent?
It's capable of dissolving more substances than any other liquid
Where in the country is the water the most acidic?
Ohio
Explain why salt dissolves in water so easily
Salt dissolves so easily due to electrical charges and salt and water have the same charges
What is the definition of surface tension?
The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules
What does it mean to have a pH of "7"?
This means it is neither acidic or basic
Where in the country is the water the most basic or alkali?
Utah
What makes water so unique?
Water is the only natural substance that is found in all three physical states at temperatures normally found on Earth
What does it mean to have a "high surface tension"?
Water tends to clump together in drops
What is the meniscus of water?
a curve in the surface of a molecular substance when it touches another material
How does the heat capacity of water help to regulate the climate and seasonal temperatures?
high heat index of water also helps regulate the rate at which air changes temperature, which is why the temperature change between seasons is gradual rather than sudden, especially near the oceans.
Why is the density of water so important to life on earth?
lakes would freeze from the bottom up killing all life in them
Can pure water be found in nature? Is pure water a good conductor of electricity?
no does not conduct electricity
What is density?
the weight for a chosen amount (volume) of the material
What is adhesion?
water is attracted to other substances
What is cohesion?
water is attracted to water
Explain how cohesion and adhesion create water droplets that stick to things.
water is highly cohesive making it the highest of the non-metallic liquids
What is the importance of the pH of water to living things?
determines the solubility and biological availability
Explain 3 real life examples of surface tension
1. small insects that weigh less than water can walk on it 2. a needle that is denser than water can float on the surface 3. common tent materials are somewhat waterproof
What is the pH range of the water in Utah?
5.3-6.3
Explain how plants and trees wouldn't survive without capillary action
Plants put down roots which carry water from soil
What does it mean to have a "high specific heat"?
The water would absorb a lot of heat before it gets hot
What is pH?
a measure of the relative amount of free hydrogen and hydroxyl ions in water
Which property of water is responsible for the meniscus?
adhesion
What is a "polar" arrangement?
allows the water molecules to become attracted to many other types of molecules
What does capillary action do for plants and animals?
allows water and its dissolved substances to move through the roots of plants and through tiny blood vessels in our body
Explain one other everyday example of capillary action
another everyday example is the drainage of constantly produced tear fluid from the eye
