Oint A: Thunder Run can hold 24 people. The weight of the roller coaster train at full capacity is 3,900 kg. The tallest hill on Thunder Run is 28 meters tall. At the top of the hill the roller coaster is moving 2 m/s. Knowing this information, calculate the PE and KE of the roller coaster at Point A

We can observe physical properties of elements and compounds without changing the substance.

Examples of physical properties: Density, color, boiling point, state of matter, appearance: dull or shiny, etc. 

But we can also observe and measure chemical properties by reacting a substance with something else. For example, like mixing baking soda and vinegar together. The vinegar reacts with the baking soda and produces carbon dioxide: a new substance. 

Some examples of chemical properties: Flammability, amount of heat that is released during combustion, toxicity (how much damage it causes to other organisms), radioactivity, and ability to oxidize (when you have metal that becomes rusty looking).