How to identify a chemical property and a chemical change?

Physical properties are the traits of an object that can be readily seen such as size, color and state. Measuring or changing these properties does not affect the chemical nature of the matter. For example, a paper that is cut into small pieces has undergone a physical change. The pieces have a different quantity, size, shape and texture than the original sheet.

Chemical properties are the characteristics that describe the composition of matter. These traits are carried by each individual atom, or part of matter. Some examples of chemical properties include combustibility, flammability and reactivity. Another way to look at this is to think of the chemical properties as potentials. Dry paper has the potential to burn; this is flammability, a chemical property. Magnesium metal has the potential to combine with oxygen and form Magnesium Oxide.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.