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