Multiple ChoiceWhen water evaporates, which of the following best describes the change that occurs?35views
Multiple ChoiceA mixture of iron filings and sulfur can easily be separated by which of the following methods?39views
Multiple ChoiceWhich type of change occurs when molten gallium solidifies to Ga(s) at its normal melting point?28views
Multiple ChoiceWhich of the following best describes what happens as matter changes state from gas to liquid?23views
Open QuestionWhich process is a chemical change? Is it burning a match, boiling water, melting ice, or breaking glass?673views1rank
Multiple ChoiceWhich of the following statements about the changes food undergoes during cooking is correct?181views
Multiple ChoiceWhen wood burns in a campfire, is this process best classified as a physical change or a chemical change?44views
Multiple ChoiceWhy is it sometimes difficult to determine whether an observed change is physical or chemical?27views
Multiple ChoiceWhich of the following is an example of a chemical change, and what type of evidence supports this classification?33views
Multiple ChoiceWhich of the following is a reliable indicator that a chemical reaction has occurred?20views