Answer:
Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons
 
        
             
        
        
        
Answer:
A
Explanation:
To calculate questions like this, you need to make use of the equation below:
E = hν
E is the energy, h is Planck's constant, and ν is the frequency.
Also, another important formula you need for this question is the following:
ν = c / λ
ν is the frequency, c is the speed of light, and λ is the wavelength.
Therefore, E = hν = hc/λ.
Also remember to convert nm wavelength to meters.
To answer the question, E = hc/λ = ((6.626*10^-34 J•s)(3*10^8 m/s))/(4.45*10-7 m) = 4.42 • 10^-19 J = A
 
        
             
        
        
        
Answer is: -963,8 kJ.
Q₁ = m(Fe) · C · ΔT₁.
C - specific heat capacity of liquid iron, C(Fe) = 0,82 J/g°<span>C.
</span>m(Fe) = 575 g.
ΔT₁ = 1181 - 1825 = -644°C.
Q₁ = -859306,5 J = -859,3 kJ.
Q₂ = m(Fe) · C · ΔT₂.
ΔT₂ = 293 - 1181 = -888°C.
C - specific heat capacity, C(Fe) = 0,44 J/g°C.
Q₂ = -224664 J = -224,66 kJ.
Q₃ =- heat of fusion, ΔH = 209 J/g.
Q₃ = 120175 J = 120,17 kJ.
Q = Q₁ + Q₂ + Q₃ = -963,8 kJ.
        
                    
             
        
        
        
100M solution so did new wells alanna annan carbonated