What is meant by pure substance

How many miles of water are produced if 5.43 mol pbo2 are consumed

According to the tide table below what time of day will the highest tide occur? (2 pt) the highest tide will occur at

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.