A nitrogen laser generates a pulse containing 10.0 mj of energy at a wavelength of 340.0 nm and has 1785 x 10¹⁹ photons in the pulse.
<h3>How many photons are in the pulse?</h3>
Energy of a single photon is
E=hcλ
E=6.626×10⁻³⁴ J s×3×108 m/s /340×10⁻⁹ m
E=6.31×10⁻¹⁹ J
Number of photons in the laser is
n=Total Energy/Energy per photon
n=10⁷×10⁻³J /5.90×10⁻¹⁹J/photon
n= 1785 x 10¹⁹ photons
To learn about photons, refer: brainly.com/question/20912241?referrer=searchResults
#SPJ4
Because the number of valence electrons of an element determines the properties and in particular the reactivity of that element.
In fact, elements of the first group (i.e. only one valence electron) have high reactivity, because they can easily give away their valence electron to atoms of other elements forming bonds. On the contrary, elements of the 8th group (noble gases) have their outermost shell completely filled with electrons, so they do not have valence electrons, and they have little or no reactivity at all.
Answer:
Both are true under specific circumstances. And are related to Boyle's law. volume and pressure in a gas are inversely proportional.
Explanation:
There is a tendency to entropy in our reality, that is, in particular true and visible with gases, they tend to occupy the whole space where they are confined, when we heat a volume of gas, then the movement of the particles and in consequence the pressure of the gas increases and to compensate this the volume tends to be increased too, according to Boyle's law. And the opposite happens when the volume is increased, then the pressure is relieved and since the particles are further one from each other, then the temperature is lower, and therefore it cools down.
