Valence electrons are the electrons in the outermost energy level of an atom — in the energy level that is farthest away from the nucleus.
I think it's A.
 
        
             
        
        
        
Nickel has a happy amount of 28 electrons.
        
                    
             
        
        
        
Liter
The Basic Unit for Volume
The liter, which is the basic unit of volume, was originally defined as the volume occupied by 1 kilogram of water, but today it's simply one-thousandth of a cubic meter
BRAINLY PLS
        
             
        
        
        
Answer:
c. selenium
Explanation:
sulfur and selenium are in the same group
 
        
             
        
        
        
Answer:
T=1022.42 N
Explanation:
Given that
l = 32 cm ,μ = 1.5 g/cm
L =2 m  ,V= 344 m/s
The pipe is closed so n= 3 ,for first over tone


f= 129 Hz
The tension in the string given as
T = f²(4l²) μ 
Now by putting the values
T = f²(4l²) μ 
T = 129² x (4 x 0.32²)  x 1.5 x  10⁻³ x 100
T=1022.42 N