Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how


What is the boiling point of water ? 100 degrees Celsius
What is the freezing point of water ? 0 degrees Celsius
What is hard water ? Water that does not easily form a later with soap.
What is soft water ? Water that easily forms a later with soap.
What causes water hardness ? The presence of calcium and/or magnesium ions.
How many stages are there in the water treatment cycle ? 5 (screening, settling, filtration,chlorination and fluoridation)
What is screening ? Screening involves using a wire mesh to filter out large, insoluble particles (e.g. twigs/branches).
What is settling ? Settling involves using settling beds to remove smaller insoluble particles.
What is filtration ? Filtration involves filtering the water through beds of sand & gravel to remove small insoluble particles.
What is chlorination ? Chlorination involves adding chlorine to kill bacteria.
What is fluoridation ? Fluoridation involves adding fluoride for healthy teeth.
How is hardness removed from water ? Hardness in water is removed by distillation or using an ion exchange resin.
How does an ion exchange resin work ? Ion exchange resin works by exchanging the calcium ions which cause hardness with hydrogen ions.
What are the advantages of hard water ? Advantages of hard water include that it tastes better, and provides calcium.
What are the disadvantages of hard water ? Disadvantages of hard water include that it causes limescale, and wastes soap.
Created by: Hannah Cassidy



Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards