Choose the correct answer for the following questions:
1. Henry come across a few posters titled as pure water, and pure gold; though these substance are not pure. What do you mean by purity of substance?
2. In an oral discussion, Vinay said that oxygen is an element. Henry said that sulphur is an element. Sam said that hydrogen is an element. The teacher then asked Sharmila whether water is an element or not. She missed the “Elements and Compounds” class. She guessed and said the incorrect answer. The teacher said it was wrong. What was the correct answer then?