How to distinguish between metals and non-metals

Explanation:

Metals tend to have 1-3 valence electrons in their outer shell, while non metals have 4-8 electrons in their outer shell. Metals are natural elements that are hard, opaque, shiny and dense. While non metals are chemical substances that are soft, transparent, non-shiny and brittle. You can also distinguish a metal from a non-metal based on its appearance: metals are Lustrous while non metals are Non-lustrous. In other words metals are shiny while non metals are usually dull or simply "not shiny". Melting and Boiling point can also help distinguish between metals and non metals: metals tend to have : very high melting and boiling point. Nonmetals have Low melting and boiling point. Metals are also good conductors of heat and electricity, while nonmetals are poor conductor of heat and electricity. And lastly, metals are malleable and are always hard except for sodium, and nonmetals are non-malleable and are soft except for diamonds.

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.