The unit expressed in 660 nm of light represents the wavelength of light. If you want to determine the frequency, you use the speed of light to relate the two. The formula is:
c = λν
where
λ is the wavelength
ν is the frequency
c is the speed of light = 3×10⁸ m
Apply SI units:
(3×10⁸ m) = (660×10⁻⁹ m)(ν)
Solving for ν,
<em>ν = 4.55×10¹⁴ s⁻¹</em>
        
             
        
        
        
One can only hold 2 electrons which only means shell two can hold 8, and for the first eighteen elements shell three can hold a maximum of eight electrons
        
             
        
        
        
Answer:
c. -1020.9 kJ
Explanation:
4Fe (s) + 3 O₂ (g) --> 2 Fe₂O₃(s)         ΔH  =  -826.0 kJ/mol.
atomic weight of iron = 56 
69.03 g = 69.03 / 56 
= 1.23268 moles 
Heat released by 1.23268 moles 
= 1.23268 x 826.0 
= -1020.9 kJ . 
 
        
             
        
        
        
Answer:
1) 0.0025 mol/L.s.
2) 0.0025 mol/L.s.
Explanation:
<em>H₂ + Cl₂ → 2HCl.</em>
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<em>The average reaction rate = - Δ[H₂]/Δt = - Δ[Cl₂]/Δt = 1/2 Δ[HCl]/Δt</em>
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<em>1. Calculate the average reaction rate expressed in moles H₂ consumed per liter per second.</em>
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The average reaction rate expressed in moles H₂ consumed per liter per second = - Δ[H₂]/Δt = - (0.02 M - 0.03 M)/(4.0 s) = 0.0025 mol/L.s.
<em>2. Calculate the average reaction rate expressed in moles CI₂ consumed per liter per second.</em>
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The average reaction rate expressed in moles Cl₂ consumed per liter per second = - Δ[Cl₂]/Δt = - (0.04 M - 0.05 M)/(4.0 s) = 0.0025 mol/L.s.