"Sigma"s between the hydrogens and the oxygen
<h3>
Answer:</h3>
4.227 × 10^-19 Joules
<h3>
Explanation:</h3>
Energy of a photon of light is calculated by the formula;
E = hf, where h is the plank's constant, 6.626 × 10^-34 J-s and f is the frequency.
But, f = c/λ
Where, c is the speed of light (2.998 × 10⁸ m/s), and λ is the wavelength.
Given the wavelength is 470 nm or 4.7 × 10^-7 m
Therefore;
E = hc/λ
= (6.626 × 10^-34 J-s × 2.998 × 10^8 m/s) ÷ 4.7 × 10^-7 m
= 4.227 × 10^-19 Joules
Therefore, the energy of a photon with 470 nm is 4.227 × 10^-19 Joules
The elements are Krypton and Xenon
Answer:

Explanation:
Given that,
Area of sheet of Aluminium foil is 1 m²
Mass of the sheet = 3.636 g
The density of Aluminium, 
We need to find the thickness of the sheet in millimeters.
The density of an object is given in terms of its mass and volume as follows :

V = volume, V = A×t, t = thickness of the sheet
So,

Since, 1 cm = 10 mm
So,
t = 0.00134 mm
or
