process by which one separates compounds from one another by passing a mixture through column that retains some compounds longer than others.
Answer:
Based on safety and carbon emissions, fossil fuels are the dirtiest and most dangerous, while nuclear and modern renewable energy sources are vastly safer and cleaner.
F = (mass)(acceleration) = ma
m = 55 kg
Vi = 20 m/s
t = 0.5 s
Vf = 0 m/s (since she was put to rest)
a=(Vf-Vi)/t
a=(0-20)/5
a = 40 m/s^2 (decelerating)
F = ma = (55 kg)(40 m/s^2)
F = 2200 N
Answer:
Argon
Explanation:
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas
hope it helps!
Answer:
(2) The lowest energy orbits are those closest to the nucleus.
Explanation:
In the Bohr theory the electrons describe circular orbits around the nucleus of the atom without radiating energy, therefore to maintain the circular orbit, the force that the electron experiences, that is, the coulombian force due to the presence of the nucleus, must be equal to the centripetal force.
The electron only emits or absorbs energy in the jumps from one allowed orbit to another, with only one jump occurring at a time, from layer K (n = 1) to layer L (n = 2), without going through intermediate orbits. In said change it emits or absorbs a photon whose energy is the difference in energy between both levels.
In Bohr's model, it is stipulated that the energy of the electron is greater the greater the radius r, so the lowest energy orbits are those closest to the nucleus.
