Science Exam IV Lesson 4

What are four ways that water quality can be

decreased?

a) Turbididty – clearness of the water

- more clear is generally better

b) Temperature – cooler water holds more dissolved

oxygen which is important for aquatic life

c) Acididty - measures the concentration of dissolved

hydrogen atoms in a water sample

- pH scale is from 1(very acidic) to 14 (very basic)

- Healthy water is pH 7 (neutral)

d) Salinity – amount of salt in water. Freshwater fish can

not exist in salt water

How are water samples tested for acidity?

o Acidity is determined by measuring the pH of a

sample (often with strips or a meter). pH values

range from 14 (very basic) to 1 (very acidic)

 distilled water (containing no other

substances) has a neutral pH 7

o the higher the dissolved hydrogen, the lower the pH

How do nuclear power plants contribute to thermal

pollution?

Thermal pollution occurs around nuclear power plants,

which return warm water to water bodies and raise their

temperature. The warmer the water, the less dissolved

oxygen (important for aquatic life) it can hold.

Why is testing for water quality so important?

Understanding the quality of the water around us is

important for maintaining health.