Answer:
Relative humidity is low .
Explanation:
The wet bulb reads low temperature because due to low humidity of atmosphere , evaporation of water takes place from the wet bulb which makes the bulb cool and therefore it reads lower temperature . In the process of evaporation , heat equal to latent heat of vaporization is taken from the bulb and it loses temperature.
Answer: -
The approximate number of atoms in a bacterium is 10¹¹
Explanation: -
We are given the mass of a bacterium is 10⁻¹⁵ kg.
We are told that the mass of a hydrogen atom is 10⁻²⁷ kg.
Finally we learn that the average mass of an atom of the bacterium is ten times the mass of a hydrogen atom.
Mass of an atom of bacterium = 10 x mass of hydrogen atom
= 10 x 10⁻²⁷ kg.
= 10⁻²⁶ kg.
Thus the number of atoms in a bacterium = 
= 
= 10¹¹
When Lead (II) acetate and Hydrogen sulfide react, they form Lead sulfide and Acetic acid. The reaction is a reduction-oxidation (redox) reaction.
The balanced chemical reaction is this:
Pb(C2H3O2)2 + H2S --> PbS + 2C2H4O2
And the net ionic reaction is this:
Pb2+ + S2- --> PbS