Answer:
When you are trying to find the middle
Explanation:
9, 9, 10.5, 11, 11.5, 12, 12
If you were asked to find the median of these numbers, all you would have to do is cross off the side numbers till you get one in the middle. Should you end up with 2 numbers as the median then I believe that you add them then divide by 2
Answer:
Zr. You should be able to see it on a periodic table.
Explanation:
Answer is: dispersion forces.
The London dispersion force is the weakest intermolecular force.
Dispersion force is also called an induced dipole-induced dipole attraction.
The London dispersion force (intermolecular force) is a temporary attractive force between molecules.
The dipole beetween iodine and bromine is weak.
Answer:
n = 2.208x10¹⁸ photons
Explanation:
The energy of a photon( an elementary particle) is given by the equation:
E = nxhxf
Where n is the number of photons, h is plank constant (6,62x10⁻³⁴ J.s), and f is the frequency. Knowing that the power level is 0.120mW (1.2x10⁻⁴ W), the energy in J, for a time of 78 min (4680 s)
E = 1.2x10⁻⁴x4680 = 0.5616 J
The frequency of a photon is its velocity ( c= 3x10⁸ m/s) divided by its wavelength, which is 780 nm = 780x10⁻⁹ m
f = 3x10⁸/780x10⁻⁹
f = 3.846x10¹⁴ s⁻¹
Then, the number of photons is:
0.5616 = nx6,62x10⁻³⁴x3.846x10¹⁴
n = 2.208x10¹⁸ photons.
It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms.
These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe. Present observations suggest that the first stars formed from clouds of gas around 150–200 million years after the Big Bang. Heavier atoms such as carbon, oxygen and iron, have since been continuously produced in the hearts of stars and catapulted throughout the universe in spectacular stellar explosions called supernovae.
