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- Substructure of the nucleus
Test prep for ap courses
A typical carbon nucleus contains 6 neutrons and 6 protons. The 6 protons are all positively charged and in very close proximity, with separations on the order of 10
-15 meters, which should result in an enormous repulsive force. What prevents the nucleus from dismantling itself due to the repulsion of the electric force?
- The attractive nature of the strong nuclear force overpowers the electric force.
- The weak nuclear force barely offsets the electric force.
- Magnetic forces generated by the orbiting electrons create a stable minimum in which the nuclear charged particles reside.
- The attractive electric force of the surrounding electrons is equal in all directions and cancels out, leaving no net electric force.
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Section summary
Conceptual questions
Problems&Exercises
Verify that a
mass of water at normal density would make a cube 60 km on a side, as claimed in
[link] . (This mass at nuclear density would make a cube 1.0 m on a side.)
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Find the length of a side of a cube having a mass of 1.0 kg and the density of nuclear matter, taking this to be
.
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Find the radius of a
nucleus.
is a manufactured nuclide that is used as a power source on some space probes.
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(a) Calculate the radius of
, one of the most tightly bound stable nuclei.
(b) What is the ratio of the radius of
to that of
, one of the largest nuclei ever made? Note that the radius of the largest nucleus is still much smaller than the size of an atom.
(a)
(b)
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The unified atomic mass unit is defined to be
. Verify that this amount of mass converted to energy yields 931.5 MeV. Note that you must use four-digit or better values for
and
.
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What is the ratio of the velocity of a
particle to that of an
particle, if they have the same nonrelativistic kinetic energy?
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If a 1.50-cm-thick piece of lead can absorb 90.0% of the
rays from a radioactive source, how many centimeters of lead are needed to absorb all but 0.100% of the
rays?
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The detail observable using a probe is limited by its wavelength. Calculate the energy of a
-ray photon that has a wavelength of
, small enough to detect details about one-tenth the size of a nucleon. Note that a photon having this energy is difficult to produce and interacts poorly with the nucleus, limiting the practicability of this probe.
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(a) Show that if you assume the average nucleus is spherical with a radius
, and with a mass of
u, then its density is independent of
.
(b) Calculate that density in
and
, and compare your results with those found in
[link] for
.
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What is the ratio of the velocity of a 5.00-MeV
ray to that of an
particle with the same kinetic energy? This should confirm that
s travel much faster than
s even when relativity is taken into consideration. (See also
[link] .)
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(a) What is the kinetic energy in MeV of a
ray that is traveling at
? This gives some idea of how energetic a
ray must be to travel at nearly the same speed as a
ray. (b) What is the velocity of the
ray relative to the
ray?
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Questions & Answers
how does Neisseria cause meningitis
is the branch of biology that deals with the study of microorganisms.
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
How bacteria create energy to survive?
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
which site have a normal flora
Many sites of the body have it
Skin
Nasal cavity
Oral cavity
Gastro intestinal tract
Safaa
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
part of a tissue or an organ being wounded or bruised.
Wilfred
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Source:
OpenStax, College physics for ap® courses. OpenStax CNX. Nov 04, 2016 Download for free at https://legacy.cnx.org/content/col11844/1.14
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