Answer:
The desert was one covered by ocean water.
Explanation:
 
        
             
        
        
        
Answer:
Gallium-72
Explanation:
The elements are identified by the number of protons of the atom, which is its atomic number.
In this case the number of protons 39 (atomic number 39) permit you to identify the element as gallium.
Now, to identify the isotope you tell the name of the element and add the mass number.
The mass number is the sum of the protons and the neutrons
In this case, the number of neutrons is the original 39 plus the 2 added suddenly, i.e. 39 + 2 = 41, so the mass number is 31 + 41 = 72
Therefore, the isotope is gallium - 72.
 
        
             
        
        
        
Answer:
The boiling point of milk is close to the boiling point of water, which is 100 degrees C, or 212 degrees F at sea level, but milk contains additional molecules, so its boiling point is slightly higher.
Explanation:
 
        
             
        
        
        
Answer:
3.4
Explanation:
The pH scale is used to express the acidity or basicity of a solution.
- If the pH < 7, the solution is acid.
- If the pH = 7, the solution is neutral.
- If the pH > 7, the solution is basic.
Given the hydronium ion concentration [H₃O⁺] = 3.8 × 10⁻⁴ M, we can calculate the pH using the following expression.
pH = -log [H₃O⁺]
pH = -log 3.8 × 10⁻⁴
pH = 3.4
This solution is acid.