The mass change, or the mass defect, can be calculated by the formula that is very known to be associated with Albert Einstein. 
E = Δmc²
where
E is the energy gained or released during the reaction
c is the speed of light equal to 3×10⁸ m/s
Δm is the mass change
(1.715×10³ kJ)(1,000 J/1 kJ) = Δm(3×10⁸ m/s)²
Δm = 1.91×10⁻¹¹ kg
        
             
        
        
        
Answer:
the input force would be 75 N
Explanation:
if the output force is 150 N you divide that in half which leaves with 75 N !! :)
 
        
             
        
        
        
Answer:
Storage solution; deionized water; stabilizes.
Explanation:
The pH scale measures the concentration of hydrogen ions in acidic and alkaline solutions.
In chemistry, it literally means power of hydrogen ions and it is a measure of the molar concentration of hydrogen ions in a particular solution, thus specifying the acidity, neutrality or basicity of chemical solutions.
Mathematically, the pH of a solution is given by;

Hence, a solution with a pH of 7 is neutral. Also, a solution with a pH below 7 is acidic but basic (alkaline) if it's pH is above 7.
A pH meter can be defined as a scientific instrument or device designed and developed for the measurement of the hydrogen-ion concentration in water-based solutions, in order to determine their level of acidity or alkanility.
When using a pH meter to take a measurement, you should keep it in a storage solution until it is needed. Also, a deionized water should be used to rinse the pH meter and gently pat dry. 
Furthermore, the pH meter should be placed in a given sample solution and a reading of the measurement taken when the pH of the solution stabilizes.
 
        
             
        
        
        
Answer:
Box is made up of <em>copper</em>, because density is <em>8.96  g/cm³.</em>
Explanation:
Given data:
Volume of box = 17.63 cm³
Mass of box = 158 g
Which metal box is this = ?
Solution:
First we will calculate the density of box then we will compare it with the density value of given metals.
d = m/v
d = 158 g/ 17.63 cm³
d = 8.96  g/cm³
The calculated density is similar to the given density value of copper thus box is made up of copper.