Multiple ChoiceWhen water evaporates, which of the following best describes the change that occurs?31views
Multiple ChoiceA mixture of iron filings and sulfur can easily be separated by which of the following methods?37views
Multiple ChoiceWhich type of change occurs when molten gallium solidifies to Ga(s) at its normal melting point?24views
Multiple ChoiceWhich of the following best describes what happens as matter changes state from gas to liquid?19views
Open QuestionWhich process is a chemical change? Is it burning a match, boiling water, melting ice, or breaking glass?666views1rank
Multiple ChoiceWhich of the following statements about the changes food undergoes during cooking is correct?174views
Multiple ChoiceWhen wood burns in a campfire, is this process best classified as a physical change or a chemical change?42views
Multiple ChoiceWhy is it sometimes difficult to determine whether an observed change is physical or chemical?23views
Multiple ChoiceWhich of the following is an example of a chemical change, and what type of evidence supports this classification?28views
Multiple ChoiceWhich of the following is a reliable indicator that a chemical reaction has occurred?17views