Answer:
Lone pairs cause bond angles to deviate away from the ideal bond angles
Explanation:
Bonded electrons are stabilized and clustered between the bonding electrons meaning they are much closer together. Non-bonding electrons however are not being shared between any atoms which allows them to roam a little further spreading the charge density over a larger space and therefore interfering with what would be an expected bond angle
 
        
             
        
        
        
1. True
2. False
Does that answer your question?
        
             
        
        
        
Mechanical wave shows dual nature
        
                    
             
        
        
        
I believe the answer is F. This is because, F stands for Fluorine, which is an element and consists of one atom. A molecule consists of TWO OR MORE atoms held together by chemical bonds. F consists of only one atom, which is Fluorine. So the answer is C. Hope helped.
        
                    
             
        
        
        
The book is lifted upward, but gravity points down, so the work done by gravity must be negative (so you can eliminate options 1 and 3).
The force exerted on the book by gravity has magnitude
<em>F</em> = <em>mg</em> = (10 N) (9.80 m/s^2) = 9.8 N ≈ 10 N
You raise the book 1.0 m in the opposite direction, so the work done is
<em>W</em> = (10 N) (-1.0 m) = -10 J