A scientist in a lab putting some chemicals into a test tube due to test the hardness of the water
A scientist holding an erlenmeyers flask and puts some chemicals into it to test the water hardness
A young scientist demonstrating water hardness test with a thumbs up
A young scientist demonstrating water hardness tests, highlighting the benefits of soft water
A scientist holding two test tubes, the result of water hardness test, one good and one bad result
A scientist in a lab putting some chemicals into an erlenmeyers flask due to test the hardness of the water - the water is soft and the content becomes blue
Time-lapse of a man checking the hardness of the water
A man checking the hardness of the water in an erlenmeyers flask-the water is soft due to the blue color
Water purification test. Drop blue liquid in test tube with clean water. Scientist doing chemical experiment
The young patient is pleased with the dentist's examination
Dental surgery: satisfied patient after surgery
A satisfied patient studies her medical certificate