4X + 3O₂ = 2X₂O₃
n(X₂O₃)=0.02225 mol
m(X)=4.000 g
x - the molar mass of metal
m(X)/4x=n(X₂O₃)/2
x=m(X)/{2n(X₂O₃)}
x=4.000/{2*0.02225)=89.89 g/mol
X=Y (yttrium)
Answer:
The energy of electron is 3.978×10⁻¹⁹ j.
Explanation:
Given data:
Energy of electron = ?
Wavelength of electron = 5.00 ×10⁻⁷ m
Solution:
Formula:
E = hc/λ
E = energy
h = planck's constant (6.63×10⁻³⁴ j.s)
c = speed of light
λ = wavelength
Now we will put the values in formula.
E = 6.63×10⁻³⁴ j.s × 3×10⁸ m/s / 5.00 ×10⁻⁷ m
E = 19.89×10⁻²⁶ j.m /5.00 ×10⁻⁷ m
E = 3.978×10⁻¹⁹ j
The energy of electron is 3.978×10⁻¹⁹ j.
