Question: What kinds of evidence indicate a chemical change has taken place? Observe: Some chemical reactions release heat, and others absorb heat. In an exothermic reaction, heat is released and the temperature of the system rises. In an endothermic reaction, heat is absorbed and the temperature of the system decreases.

In the Gizmo, drag the Thermometer into the flask of water.

A.

What is the starting temperature?

B.

Click Play, and wait for the reaction to end. What is the final temperature?

C.

Was this reaction exothermic or endothermic?

Both josef loschmidt and amedeo avogadro contributed to our understanding of basic molecular numbers, sizes, and reaction ratios. neither scientist discovered “avogadro’s number” in the form we use it today (6.02 x 10 23). still, there’s a controversy over the name. research the contributions from these two scientists and read about how avogadro’s number got its name. briefly state what you think this number should be called, providing key details of each scientist’s contributions to this concept and a solid rationale for your case in naming the number.

The tendency of water molecules to stick together is referred to as a) adhesion b) polarity c) cohesion d) transpiration e) evaporation

Answer explain why it is not possible to deduce a complete order of reactivity.