What is the energy of one photon of red light that has a wavelength of 678 nm? O 2.93 x 10^-19)
O 2.93 x 10^-37)
O 4.42 x 10^-4)
O 6.78 x 10^-7)
PLEASE HELP

E = 2.93×10⁻¹⁹ J

Explanation:

Given data:

Wavelength of photon = 678 nm   (678×10⁻⁹ m)

Energy of photon = ?

Solution:

Formula:

E = h c/λ

h = 6.63×10⁻³⁴ Js

c = 3×10⁸ m/s

E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 678×10⁻⁹ m

E = 19.89 ×10⁻²⁶ Jm / 678×10⁻⁹ m

E = 0.0293×10⁻¹⁷ J

E = 2.93×10⁻¹⁹ J

it's all four options.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72