Answer: He spends 29.17 hours per week 
Explanation:
1 class = 50mins
7 classes = 7 x 50mins = 350mins
For 5 days in a week, we have 
5 x 350mins = 1750mins
Converting to hours, we have
1750 /60 = 29.17 hours 
 
        
             
        
        
        
The answer is 3.5 × 10^-3
        
             
        
        
        
Answer:
<em>Hydrogen.</em>
Explanation:
You've probably seen "
" which is the formula for water. It means that there's 2 hydrogen atoms, and one oxygen atom, in one molecule of water.
<em>Hope this helps! Feel free to mark me Brainliest if you feel this helped. :)</em>
 
        
                    
             
        
        
        
Hydrogen and oxygen cn form a polar covalent bond
        
             
        
        
        
 4.648 gm of solute is needed to make 37.5 mL of 0.750 M KI solution.
Solution:  
We will start with the Molarity  

Also we know 1000 ml = 1 L
Therefore 37.5 ml by 1000ml we obtained 0.0375L  
Equation for solving mole of solute
 
Now, multiply 0.750M by 0.0375
Substitute the known values in the above equation we get

Also we know that Molar mass of KI is 166 g/mol
So divide the molar mass value to get the no of grams.

So 4.648 gm of Solute is required for make 37.5 mL of 0.750 M KI solution.