Match the following chemical reactions:
synthesis, reversible, exchange, decomposition

1. molecules rearrange and form new molecules
2. simultaneous decomposition and synthesis
3. bonds broken and elements released
4. molecules formed from components

Synthesis - 4

reversible- 2

exchange- 1

decomposition-3

Explanation:

In synthesis reaction two or more components combines to form a single product. example 2H2+O2⇒2H2O

In reversible reaction two reactants combine to form two products . The products then reacts and forms back the reactants. example N2 +3H2 ⇒2NH3

In exchange reaction there is an alternation of ions of reactants to form new products. AB+CD ⇒AC + BD

In decomposition reaction, molecules of a compound break down by the action of heat or light or catalyst. example CaCO3 ⇒CaO +CO2

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers

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.