From the list below, identify which situation(s) contain chemical changes.

i) a pot of water is being heated on a stove. bubbles form and condensation appears on the lid of the pot.

ii) a translucent, blue copper (ii) sulfate solution is mixed with another solution and changes to a translucent lighter blue color.

iii) ammonium nitrate solid dissolves in water and feels very cold.

iv) red and blue paint are mixed together and the color purple appears.

the answer is 3

Explanation:

any change that omits a temperature reaction is a chemical reaction. mixing paint is a physical change as the paint itself is not effected om the chemical level.

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.