Question

The number of photons of light having wavelength 450 nm which can provide 100 J of energy is equal to (n = 6.6 x 10-34 J s)

•1.2 x 1020

•2.3 x 1020

•2.8 x 1018

•2.3 x 1017​

Answer 1

Answer:

2.3×10²⁰

Explanation:

E= n×h×v

given that wavelength =450nm

thus

$v = \frac{c}{lamda}$

so v=

$\frac{3 \times {10}^{8} }{450 \times {10}^{ - 9} } = \frac{ {10}^{16} }{15}$

n=E/hv

$\frac{100 \times 15}{6.626 \times {10}^{ - 34} \times {10}^{16} }$

=2.26×100×10¹⁸

thus, 2.3 ×10²⁰

hope it helps:)