Reactive Phosphorous

[exchemist]

It's  over my head but I want to work on it. I am wondering if it is lead that patients are protected from when undergoing CAT scans.  It must be powerful since the technicians leave the room during the process.  Did you know that, at one time, radioactivity was considered beneficial to our well-being?  And Marie Curie died of leukemia.  "Radioactive mineral springs" - a vacation spot.

 

Last night, just by coincidence, I read the story of how lead got into  gasoline - and how it got out again amid horrible protests from those getting rich on ethyl gasoline.  I do remember how people wanted ethyl gasoline if they could afford  the extra cost.  It prevented knocking in the engine. Then there are/were chlorofluorocarbons.  Same story.  ("A Short History of Nearly Everything" by Bill Bryson.)

 

By the way are these elements that other elements decay into all isotopes?

A CAT scan uses X-rays so lead shielding would be effective. Operators leave the room because if they didn't they would quickly clock up many hundreds of times the exposure that any one patient is subjected to. 

 

Tetra ethyl lead was developed by an American called Thomas Midgeley, who, seen from today's perspective, appears as a curious mixture of heroic chemist, villain and comic idiot:  https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.  His death, in particular, is worthy of an Evelyn Waugh novel. :)

 

P.S. Re isotopes, every version of every element is an isotope. The term is from the Greek meaning "same place" and refers to the possibility of multiple atomic weights for the same element, i.e. occupying the same place in the Periodic Table. For example lead in nature consists of a mixture of lead 204, 206, 207 and 208.  These all have different numbers of neutrons in the nucleus, but because they have the same number of protons (82), they all have 82 electrons to balance the electric charge of the nucleus (+82) and thus are all the same element, lead.

 

Isotopes that are not stable and are radioactive (giving off alpha particles, beta particles or gamma rays as they decay) are called "radioisotopes". It is this type of isotope that is the context in which most people have heard the term.  But really it means just a  particular version of a given element, defined by a certain number of neutrons in its nucleus.  

Edited January 21, 2019 by exchemist

[hazelm]

A CAT scan uses X-rays so lead shielding would be effective. Operators leave the room because if they didn't they would quickly clock up many hundreds of times the exposure that any one patient is subjected to. 

 

Tetra ethyl lead was developed by an American called Thomas Midgeley, who, seen from today's perspective, appears as a curious mixture of heroic chemist, villain and comic idiot:  https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.  His death, in particular, is worthy of an Evelyn Waugh novel. :)

 

P.S. Re isotopes, every version of every element is an isotope. The term is from the Greek meaning "same place" and refers to the possibility of multiple atomic weights for the same element, i.e. occupying the same place in the Periodic Table. For example lead in nature consists of a mixture of lead 204, 206, 207 and 208.  These all have different numbers of neutrons in the nucleus, but because they have the same number of protons (82), they all have 82 electrons to balance the electric charge of the nucleus (+82) and thus are all the same element, lead.

 

Isotopes that are not stable and are radioactive (giving off alpha particles, beta particles or gamma rays as they decay) are called "radioisotopes". It is this type of isotope that is the context in which most people have heard the term.  But really it means just a  particular version of a given element, defined by a certain number of neutrons in its nucleus.  

My misunderstanding of isotopes.  I thought isotopes were elements that had lost or gained an extra electron.  Thank you

[exchemist]

My misunderstanding of isotopes.  I thought isotopes were elements that had lost or gained an extra electron.  Thank you

Ah no. Those would be ions.

 

For example, Sodium, Na, gives an electron to Chlorine, Cl, to make Na+Cl-, common salt. An example of an ionic compound.

 

Sodium easily gives up one electron because it has 11 of them, 10 of which fill up the first 2 electron shells so the last one has to go into a new shell (shell no.3) , which is further out from the nucleus and only weakly bound by electrostatic attraction. So sodium likes to form Na+ ions.

 

Chlorine has 6 more electrons than sodium so it has got 7 electrons in shell number 3, which leaves a a gap for one more before the shell is full. And the charge on the nucleus has gone up by 6, so the electrons in shell no.3 are being pulled in more strongly. So chlorine likes to form Cl- ions.

 

By trading one electron between them, a weak Na-electron attraction is replaced by a strong Cl-electron attraction,  the total energy of the system goes down and hence NaCl is more stable than Na metal and Chlorine gas. As you find out very quickly indeed if you ever put a piece of sodium metal in a jar of chlorine gas!     

[hazelm]

Ah no. Those would be ions.

 

For example, Sodium, Na, gives an electron to Chlorine, Cl, to make Na+Cl-, common salt. An example of an ionic compound.

 

Sodium easily gives up one electron because it has 11 of them, 10 of which fill up the first 2 electron shells so the last one has to go into a new shell (shell no.3) , which is further out from the nucleus and only weakly bound by electrostatic attraction. So sodium likes to form Na+ ions.

 

Chlorine has 6 more electrons than sodium so it has got 7 electrons in shell number 3, which leaves a a gap for one more before the shell is full. And the charge on the nucleus has gone up by 6, so the electrons in shell no.3 are being pulled in more strongly. So chlorine likes to form Cl- ions.

 

By trading one electron between them, a weak Na-electron attraction is replaced by a strong Cl-electron attraction,  the total energy of the system goes down and hence NaCl is more stable than Na metal and Chlorine gas. As you find out very quickly indeed if you ever put a piece of sodium metal in a jar of chlorine gas!     

Ah, yes.  Word  mixup.  Ions.  Thanks.