Answer:
Primer postulado:
Así Bohr asumió que el átomo de hidrógeno puede existir solo en ciertos estados discretos, los cuales son denominados estados estacionarios del átomo. En el átomo no hay emisión de radiación electromagnética mientras el electrón no cambia de órbita.
Explanation:
Positron emission = emission of a positron and a neutrino when a
proton is convert into a neutron. The total number of particles in the
nucleus doesn't change, -1 proton +1 neutron
It's a spontaneous reaction for some nucleus.
eg:
Positron = e+
Neutrino=ve
O-15 --> N-15 + e+ +ve
Electron
capture= A nucleus absorb an electron while a proton is convert in a
neutron and emit a neutrino. The total number of particles in the
nucleus doesn't change, -1 proton +1 neutron
eg:
Al-26 +e- --> Mg-26 + ve
Electron
capture and positron emission are two mechanisms to explain the decay
of some unstable isotopes. Electron capture is usually observed when the
energy difference between the initial and final state is low. Mainly
because of the larger amount of kinetic energy need for the expulsion
two particles with the positron emission mechanism.
Before the development of electrophoresis to separate macromolecules, high-speed centrifugation was used to isolate DNA.
A laboratory procedure called electrophoresis is used to divide DNA, RNA, or protein molecules according to their size and electrical charge. The molecules are moved by an electric current through a gel or other matrix. The technology of electrophoresis is crucial for the separation and examination of nucleic acids. At the lab bench, cloned DNA fragments are frequently isolated and worked with using nucleic acid electrophoresis.
High-speed centrifugation employs centrifugal force to separate particles with various densities or masses suspended in a liquid. High-speed rotation of the solution inside the tube causes each particle's angular momentum to experience centrifugal forces inversely proportionate to its mass.
To know more about electrophoresis refer to: brainly.com/question/28709201
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Answer:
Density is an intensive property
Explanation:
The intensive properties don´t depend on mass or size, if you have a liter of water, this litter have a density equal 1000 kg/m^3. If zo have 250 liters of water, the density is 1000 kg/m^3 too.
The density does not change with the addition or substraction of matter.
I hope I have been clear.
