Which is an example of a chemical change

a.) a candle burns

b.) a pan of water boils

c.) a teaspoon of salt dissolves

d.) a burner gets red hot

A skateboarder reaches a speed of 130 km/h while attempting to set a world record. At this speed, how far would the skateboarder go in 30 minutes? A. 45 km B. 65 km C. 75 km D. 95 km

What is the definition of electrical energy?

What role do aquifers play in the water cycle

Classify the following compounds as having covalent or ionic bondsa. dinitrogen trioxideb. carbon dioxidec. calcium chlorided. magnesium nitridee. sodium bromidef. aluminum oxide

A sample of nitrogen gas expands in volume from 1.3 to 5.7 L at constant temperature. Calculate the work done in joules if the gas expands (a) against a vacuum: J (b) against a constant pressure of 0.

The word atom means invisible?

A pycnometer weighs 25.60 g empty and 35.55 g when filled with water at 20°C. The density of water at 20°C is 0.9982 g/ml. When 10.20 g lead is placed in the pycnometer and the pycnometer is again filled with water at 20°C, the total mass is 44.83 g.

How does weathering affect the surface area of a rock? Explain your answer.

How would each of the following procedural errors affect the results to be expected in this experiment? Give your reasoning in each case. (A) Not all of the liquid was vaporized when the flask was removed from the water bath.

What volume of 2.00 m must be added to 150.0 ml of 1.00 m chloroacetic acid to produce a buffer solution having a ph of 3.30?