Questions

Air Pressure can be defined as the pressure of air in the earth's atmosphere. It reaches a maximum of about 100,000 Pa near sea level and decreases as altitude increases.

The barometer is an instrument which is used for measuring Air pressure.

Physics instruments and their uses:

Barkometer  - - - Tanning liquors used in tanning leather

Bolometer  - - - Electromagnetic radiation

Spectrometer - - -  Properties of light.

The gram formula mass is nothing but molar mass.

Composition :

Symbol      Element       Atomic weight       Atoms
   

     P         Phosphorus       30.973762               1       = 30.973
   

     O         Oxygen             15.9994                  4       =  63.998
   

     N         Nitrogen            14.0067                  3       =  42.020
   

     H         Hydrogen          1.00794                  12      =  12.096

Total   =  30.973+63.998+42.020+12.096 = 149.087

Hierarchy is a system of ranking in which members of a particular society are ranked in an ascending order depending on various factors.

Hence, the term hierarchy refers to a power structure in which each member knows his or her own place.

Jello is a colloid, a semi-rigid structure i.e, semi-solid suspended in a liquid. When you Heat it up a bit and you'll break the protein bonds of the gelatin and it will liquefy completely and if you freeze, it becomes solid.