Answer:
IV
Explanation:
The complete question is shown in the image attached.
Let us call to mind the fact  that the SN1 mechanism involves the formation of carbocation in the rate determining step. The order of stability of cabocations is; tertiary > secondary > primary > methyl.
Hence, a tertiary alkyl halide is more likely to undergo nucleophilic substitution reaction by SN1 mechanism since it forms a more stable cabocation in the rate determining step.
Structure IV is a tertiary alkyl halide, hence it is more likely to undergo nucleophilic  substitution reaction by SN1 mechanism.
 
        
             
        
        
        
Answer : Electron P has greater energy difference than the Electron N.
Explanation :  
Wavelength range of violet light = 400 - 500 nm
Wavelength range of orange light = 600 - 700 nm
The Planck's equation is,

where,
E = energy of light
c = speed of light
 = wavelength of light
According to the Planck's equation, wavelength and energy follow inverse relation. As the wavelength increases, energy decreases.
From the given spectrum, the wavelength of violet light is less. We conclude that When electron P gives violet light on transition it means that energy difference between the energy level was high.
From the given spectrum, the wavelength of orange light is more. We conclude that When electron N  gives orange light on transition it means that energy difference between the energy level was low. 
So, Electron P which gives violet light on transition has greater energy difference than the Electron N.
 
        
                    
             
        
        
        
Hydrogen sulfide = hidrogen + sulfur
       6.500 g                       
a)                             0.384 g   +    x
=> 6.500 = 0.384 + x => x = 6.500 - 0.384 = 6.116 g
Answer: 6.116 g of sulfur must be obtained
b) this experiment demonstrate the conservation of mass.
c) Dalton's atomic model states that the atoms cannot be created, split or be destroyed, and so in a chemical reaction the atoms rearrange but the number of each type of atoms remain constant, so the mass of each type of atoms and the total mass remain constant.
        
             
        
        
        
Your answer is B because elements within the same column have equal numbers of valence electrons which determines the reactivity of an element. 
        
             
        
        
        
Answer:
Reaction a: chemical, reaction b: nuclear
Explanation: