I think the best answer that will describe chemical change is the first option. During a chemical change, b<span>oth the identity and the properties of a substance change because new substances are being formed by a chemical reaction. An example is rusting of steel</span>
        
                    
             
        
        
        
Answer:
390 m
Explanation:
Martha ran 420 m
 Cole ran 60 m less than Martha = 420 m - 60 m = 360 m
The distance Kate ran is right in the middle of Martha and Cole's distances
Kate distance = (420 + 360) / 2 = 780 / 2 = 390 m
 
        
             
        
        
        
Answer:
V = 12.93 L 
Explanation:
Given data:
Number of moles = 0.785 mol
Pressure of balloon = 1.5 atm
Temperature = 301 K
Volume of balloon = ?
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K  
T = temperature in kelvin
Now we will put the values.
V = nRT/P
V = 0.785 mol × 0.0821 atm.L/ mol.K × 301 K / 1.5 atm
V = 19.4 L /1.5 
V = 12.93 L 
 
        
             
        
        
        
Answer:
E. better schools
Explanation:
This contributes the most to human development in his community because it provides children with more resources and better opportunities than a sub-par education system. If a community is able to better their school system, they will begin to see a lot of positive changes in their area. 
 
        
                    
             
        
        
        
The mole fraction of a product is the number of moles of the product divided by the total number of moles of the solution.
Here moles of methanol = 6.0 moles
Moles of solution = 6.0 moles of methanol + 3.0 moles of water = 9.0 moles of solution
Mole fraction of methanol = 6.0 / 9.0 = 0.67
Answer: 0.67