B. Mn + NiBr₂  →  Ni + MnBr₂
Explanation:
The reaction that can be predicted of all is Mn + NiBr₂  →  Ni + MnBr₂.
The activity series is used to predict the products of single displacement reactions. 
The series ranks metals in order of their reactivity. Those higher up in the series are highly reactive metals. Those at the bottom are slightly to non-reactive metals. 
 For a single displacement reaction to occur, a metal higher up in the activity series displaces one that is lower in the series. 
   Reaction A will not occur, Ba is higher in the series
   Reaction C will not occur, Pt and Au are unreactive
   Reaction D will not occur as Zn is lower in the series
Mn is higher in the reactivity series and it will displace Ni from the solution. 
Learn more: 
Synthesis reaction brainly.com/question/4216541
#learnwithBrainly
 
        
             
        
        
        
Answer:
Rubidium
Rubidium is the first element placed in period 5. 
 
        
             
        
        
        
Correct Answer: The Sun heats the Earth unevenly; this heating pattern then causes convection currents in the atmosphere.
        
             
        
        
        
Answer:
22.27 °C = ΔT
Explanation:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m × c × ΔT
Given data:
mass = 28 g
heat absorbed = 58 cal
specific heat of copper =  0.093 cal/g .°C
temperature change =ΔT= ?
Solution:
Q = m × c × ΔT
58 cal = 28 g × 0.093 cal /g.°C × ΔT
58 cal = 2.604 cal.°C × ΔT
58 cal / 2.604 cal .°C = ΔT
22.27 °C = ΔT
 
        
             
        
        
        
I think it’d be C. I’m not 100% if it is tho