X-rays had a frequency of about 3x10^18 determine it's wavelength (in nm) and energy per photon

λ = 0.1 nm

E = 2 × 10⁻¹⁵ J

Explanation:

Step 1: Given data

Frequency of X-rays (ν): 3 × 10¹⁸ s⁻¹

Step 2: Calculate the wavelength (λ) of a photon of X-rays

We will use the following expression.

c = λ × ν

where,

c: speed of light

λ = c / ν

λ = (3.00 × 10⁸ m/s) / 3 × 10¹⁸ s⁻¹

λ = 1 × 10⁻¹⁰ m × (10⁹ nm/1 m) = 0.1 nm

Step 3: Calculate the energy (E) of a photon of X-rays

We will use the following expression.

E = h × ν

where,

h: Planck's constant

E = 6.63 × 10⁻³⁴ J.s × 3 × 10¹⁸ s⁻¹

E = 2 × 10⁻¹⁵ J

the answer your looking for is c).