In terms of disorder and energy, systems in nature have a tendency to undergo changes toward

less disorder and lower

energy

less disorder and higher energy

greater disorder and lower energy

greater disorder and higher energy

Option C is correct

Explanation:

Entropy is defined as the randomness in a system. In nature, a system tends to have high entropy. The higher the entropy , the spontaneous the reactions would be. As a system loses energy, it becomes more ordered and less random. Hence, as the reaction proceeds in a system, the system  has higher energy/entropy and less order.  

Hence, option c is correct

passing a magnet thought the

mixture , because iron gets attracted to magnet .

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.