Answer:
so the answer is this because the answer is that 
Explanation:
and the reason why the answer is this and that is because the answer is that 
 
        
             
        
        
        
The idea that "students ' immune systems have declined due to the use of hand sanitizers " is a hypothesis.
The term hypothesis refers to an intelligent guess or idea often based which is subject to scientific investigation via experiments.
A hypothesis may be right or wrong. We can only prove a hypothesis by subjecting it to a series of rigorous experiments.
Thus Collette's idea is a hypothesis.
Learn more: brainly.com/question/18284466
 
        
             
        
        
        
The less valence electrons the more reactive the element is.
        
             
        
        
        
A = 15, B = 1
48 + 15 = 63 for the first 86km
43 - 1 = 42 for the remaining 54 km
time = distance/speed
t1 = 86/63 = 1.3651hours
t2 = 54/42 = 1.2857hours
speed = distance/time
s = 140/2.6508
average speed = 52.8km/h