Answer: B) Bones
Explanation:
Natural casts form when flowing water removes all of the original bone or tissue, leaving just an impression in sediment.
Volume= Mass/ Density= 20/184
= 0.108 cubic cm
Answer:-
and
radiation.
Explanations:- Alpha particle is helium nucleus with two protons and two neutrons and so it has +2 charge where as gamma is a form of light, so these are rays and not particles. Since these are rays, the charges for gamma rays is zero means they are neutral.
When alpha particles are passed through electromagnetic field they are repelled by the positive plate and attracted by the negative plate as there is an attraction between opposite charges. So, the line we see towards positive plat is representing an alpha particle radiation.
Since gamma rays are neutral, they are not deflected in electromagnetic field and go straight. So, the other line in the diagram is representing gamma rays radiation.
Answer:
Pb2+ (aq) & 2Br- (aq) --> PbBr2 (s).
Explanation:
Equation of the reaction:
Pb(C2H32O2)2 (aq) + 2 NH4Br (aq) --> 2NH4C2H3O2 (aq) + PbBr2 (s)
Ionic equation:
Pb+2(aq) + 2(C2H3O2)-1 (aq) + 2(NH4+) (aq) + 2Br-1 (aq) --> 2(NH4+) (aq) + 2(C2H3O2-) (aq) + PbBr2 (s)
2(NH4)+1(aq) & 2(C2H3O2)-1 (aq) cancel out from both sides, you are left with the net ionic equation :
Pb2+ (aq) & 2Br- (aq) --> PbBr2 (s).
Answer: B. A secondary pollutant
An acid rain is an example of a secondary pollutant because it is a chemical reaction of two gases namely, the sulfur dioxide and the nitrogen dioxide. The acid rain is not also directly emitted by the atmosphere.