Answer:
A. The model could not explain how alpha particles could be deflected at large angles.
Explanation:
The plum pudding model of the atom was proposed by J. J Thomson. He suggested that that an atom is made up of dense particles of electrons surrounded by positive charges.
From the Gold foil experiment carried out by Ernest Rutherford, he noticed that the bulk of the alpha particles targeted at the foil passed through and a little fraction was heavily deflected back.
Rutherford then presented his nuclear model from here. He suggested a massive, dense and tiny nucleus where the protons and neutrons are located. The space outside the mass is dominated by orbiting electrons.
Answer:
Pb2+(aq) + 2Cl–(aq) ----> PbCl2(s)
Explanation:
The net ionic equation shows the main reaction that takes place in a system. Hence, a net ionic equation focusses only on those species that actually participate in the reaction.
For the reaction between Pb(NO3)2 and NH4Cl , the net ionic equation is;
Pb^+(aq) + 2Cl^-(aq) ---> PbCl2(s)
The overall reaction is given by:
The fast step reaction is given as:
The slow step reaction is given as:
(slow step 
)
Now, the expression for the rate of reaction of fast reaction is:
![r_{1}=k_{1}[NO][Br_{2}]-k_{-1}[NOBr_{2}]](https://tex.z-dn.net/?f=r_%7B1%7D%3Dk_%7B1%7D%5BNO%5D%5BBr_%7B2%7D%5D-k_%7B-1%7D%5BNOBr_%7B2%7D%5D)
The expression for the rate of reaction of slow reaction is:
![r_{2}=k_{2}[NOBr_{2}] [NO]](https://tex.z-dn.net/?f=r_%7B2%7D%3Dk_%7B2%7D%5BNOBr_%7B2%7D%5D%20%5BNO%5D)
Slow step is the rate determining step. Thus, the overall rate of formation is the rate of formation of slow reaction as ![[NOBr_{2}]](https://tex.z-dn.net/?f=%5BNOBr_%7B2%7D%5D)
takes place in this reaction.
The expression of rate of formation is:
= ![k_{2}[NOBr_{2}][NO]](https://tex.z-dn.net/?f=k_%7B2%7D%5BNOBr_%7B2%7D%5D%5BNO%5D)
(1)
Now, consider that the fast step is always is in equilibrium. Therefore, 
![k_{1}[NO][Br_{2}]= k_{-1}[NOBr_{2}]](https://tex.z-dn.net/?f=k_%7B1%7D%5BNO%5D%5BBr_%7B2%7D%5D%3D%20k_%7B-1%7D%5BNOBr_%7B2%7D%5D)
![[NOBr_{2}] = \frac{k_{1}}{k_{-1}}[NO][Br_{2}]](https://tex.z-dn.net/?f=%5BNOBr_%7B2%7D%5D%20%3D%20%5Cfrac%7Bk_%7B1%7D%7D%7Bk_%7B-1%7D%7D%5BNO%5D%5BBr_%7B2%7D%5D)
Substitute the value of in equation (1), we get:
![\frac{d(NOBr)}{dt}=k_{2}[NOBr_{2}][NO]](https://tex.z-dn.net/?f=%5Cfrac%7Bd%28NOBr%29%7D%7Bdt%7D%3Dk_%7B2%7D%5BNOBr_%7B2%7D%5D%5BNO%5D)
=![k_{2} \frac{k_{1}}{k_{-1}}[NO][Br_{2}][NO]](https://tex.z-dn.net/?f=k_%7B2%7D%20%5Cfrac%7Bk_%7B1%7D%7D%7Bk_%7B-1%7D%7D%5BNO%5D%5BBr_%7B2%7D%5D%5BNO%5D)
= ![\frac{k_{1}k_{2}}{k_{-1}}[NO]^{2}[Br_{2}]](https://tex.z-dn.net/?f=%5Cfrac%7Bk_%7B1%7Dk_%7B2%7D%7D%7Bk_%7B-1%7D%7D%5BNO%5D%5E%7B2%7D%5BBr_%7B2%7D%5D)
Thus, rate law of formation of 
in terms of reactants is given by .
STP is the abbreviation of standard condition for temperature and pressure which is 273.15K temperature and 1.013× 10^5 Pa pressure. Since the pressure and temperature changes, I assume the question would ask about the result of the volume. The temperature used in ideal gas should be Kelvin, so 27 Celcius would be 300.15K.
The calculation would be
PV=T
V=T/P
V2/V1= T2*P1/T1*P2
V2/V1=273.15K* 90^10^3Pa/ 300.15K * 1.013× 10^5 Pa
V2= 0.81904 * 51.7ml
V2= 42.34ml
Natural selection makes it so that an organism from a species has a better chance of surviving than an organism in the same species, but with different traits. Survival of the fittest proves that certain traits can help an organisms survive better than its peers. For example, say there was an allele that made bears have thicker fur than others. The year-round climate is extremely cold. The bears with thicker fur are more likely to survive due to the warmth their fur provides and will have more offspring. The bears with thinner fur will die more often and not produce healthy offspring due to the frigid temperature. Eventually, the allele for thin fur will die out because the bears with these alleles cannot survive in their habitat.
