The aufbau principle, from the German Aufbauprinzip (building-up principle), also called the aufbau rule, states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels.
Answer:
Hello your question is poorly written below is the well written question
Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes, U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth
Answer : 140 billion years
Explanation:
Given that :
U-238 h1/2 = 4.5 billion years
U-235 h1/2 = 700 million years
At the beginning both Isotopes where present in equal amount
Determine the T years before the amount of Uranium decays to Half
T = ? N'2 = N1 / 2
we know that N = No ( 1/2 )^h where h = time / half-life time
attached below is the detailed solution of the given problem
Answer: the sum of the partial pressures of the individual gases.
Explanation:
According to Dalton's Law of partial pressure, the total pressure of a mixture of gases is equal to the sum of the partial pressures which each individual gas would exert if it were confined alone in the volume occupied by the mixture.
Hence, Ptotal = P1+ P2
where Ptotal is the total pressure
P1 and P2 are the partial pressures exerted seperately by the individual gases 1 and 2 that make up the mixture.
Answer:
The main difference between evaporation and boiling are : 1. Evaporation takes place at all temperatures, while boiling occurs at a particular temperature. 2. Evaporation takes place from the surface, whereas the entire liquid boils. 3. Evaporation can occur using the internal energy of the system, while boiling requires an external source of heat.