A teacher has found two white powders on a desk in the chemistry laboratory. she wants to test to see if they are pure substances, so she measures the melting points. substance X melts at 122 and substance Y melts between 87 and 93. explain which one is a pure substance

Avariable that is not being directly tested during an experiment should be

An object displaces 652 ml of water. the volume of the object is: 0.652 cm³ 6.52 cm³ 65.2 cm³ 652 cm³

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?