if we used electricity to separate water into oxygen and hydrogen. Could we use hydrogen and somehow set it to a positive or negative energy set? After that, the we would heat it up so the atoms are moving so fast that they hit into each other creating friction or heat. Is this another way of fusion reacting.

Water molecules can be broken down into hydrogen and oxygen molecules by a chemical reaction called electrolysis. When an electric current is passed through liquid water (H2O), it changes the water into two gases—hydrogen and oxygen. The molecules of water break apart into individual atoms.

Explanation:

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.