Answer:
So, Luke and Sian has to increase the pH of the soil by adding base to it.
Explanation:
The pH is defined as the negative logarithm of the hydrogen ion concentration in their aqueous solution.
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
- With increase in hydrogen ion concentration the pH value decreases.
- With decrease in hydrogen ion concentration the pH value increases.
 The pH of the soil after testing it on a kit comes out be 5.0, but they both need pH of the soil to 6.5.
Comparison of pH of soil:
   =  5.0 < 6.5
 = High hydrogen ion concentration > High hydrogen ion concentration
So, Luke and Sian has to increase the pH of the soil by adding base .Doing so will decrease the hydrogen ion concentration in the soil (where as addition of acid lower the pH of soil).
 
        
             
        
        
        
Answer:
C. Mutations are a change in DNA or a chromosome and can be helpful, harmful or may have no affect. 
Explanation:
- Mutations are spontaneous random changes that occurs in the genetic make up of an organisms. Mutations are rare and their rate of occurrence is random.
- Mutations may occur on the gene level known as gene mutations or at chromosome levels called chromosomal mutations.
- Mutations may be beneficial, harmful or have no effect on a given organisms. Harmful mutations cause disorders that may lead to abnormality or death of an organisms. Beneficial mutations improve an organisms adaptability to the environment.
 
        
             
        
        
        
Answer: picture shows work for # 1,2,4,5,7
Explanation: 
number 3: as the pressure in the volume decreases, the volume increases causing it to expand and eventually blow.
number 6: because the temperature and the amount of gas don’t change, these terms don’t appear in the equation. What Boyle’s law means is that the volume of a mass of gas is inversely proportional to its pressure. This linear relationship between pressure and volume means doubling the volume of a given mass of gas decreases its pressure by half.
hope this helps :))
 
        
             
        
        
        
Answer:
B
Explanation:
you're moving the decimal 8 spots to the left so it can only be B
 
        
             
        
        
        
Molar mass :
Li₂S = <span>45.947 g/mol
AlCl</span>₃ = <span>133.34 g/mol
</span><span>3 Li</span>₂<span>S + 2 AlCl</span>₃<span> = 6 LiCl + Al</span>₂S₃
3 * 45.947 g Li₂S ----------> 2 * <span>133.34 g AlCl</span>₃
1.084 g Li₂S ----------------> ?
Mass Li₂S = 1.084 * 2 * 133.34 / 3 * 45.947
Mass Li₂S = 289.08112 / 137.841
Mass Li₂S = 2.0972 g 
hope this helps!