Fluorine is the most reactive and the most electronegative of all the elements. Fluorine is a pale yellow, diatomic, highly corrosive, flammable gas, with a pungent odor. It is the lightest halogen.
 
        
             
        
        
        
Answer:i
9E13 ELECTRONS
Explanation:
First we find the number of charges in two hrs
Which is - 2x 7200=- 14400NC
So no of electrons is now q/e
-144x10^-7/-1.6*10^-19
= 9*10^13
 
        
             
        
        
        
Answer:
From certain assumptions that the walking speed is 2 m/s, and the stop time is 0.1 s the acceleration would be -20 m/s
Explanation:
Using the average acceleration formula:
 where
 where  and
 and  are the changes in the speed and time respectively.
 are the changes in the speed and time respectively. 
We have by assuming that the walking speed is 2 m/s and the stop time is 0.1s which is equal to the change in time during the stopping.
 , where
, where  are the initial speed and final speed respectively, and
 are the initial speed and final speed respectively, and 
Plugging the previous in the average acceleration formula we get
 where the minus sign indicates an acceleration in the opposite direction of the motion (or in other word opposite to the speed's direction).
 where the minus sign indicates an acceleration in the opposite direction of the motion (or in other word opposite to the speed's direction).
 
        
             
        
        
        
Air resistance fefrgtdnjrcbrdg
        
             
        
        
        
<span>Since there is no friction, conservation of energy gives change in energy is zero
Change in energy = 0
Change in KE + Change in PE = 0
1/2 x m x (vf^2 - vi^2) + m x g x (hf-hi) = 0
1/2 x (vf^2 - vi^2) + g x (hf-hi) = 0
(vf^2 - vi^2) = 2 x g x (hi - hf)
Since it starts from rest vi = 0
Vf = squareroot of (2 x g x (hi - hf))
For h1, no hf
Vf = squareroot of (2 x g x (hi - hf))
Vf = squareroot of (2 x 9.81 x 30)
Vf = squareroot of 588.6
Vf = 24.26
For h2
Vf = squareroot of (2 x 9.81 x (30 – 12))
Vf = squareroot of (9.81 x 36)
Vf = squareroot of 353.16
Vf = 18.79
For h3
Vf = squareroot of (2 x 9.81 x (30 – 20))
Vf = squareroot of (20 x 9.81)
Vf = 18.79</span>