Question

What does the following element description actually mean?

iron-57

a.
iron with 57 neutrons

b.
iron with a mass number of 57

c.
iron with 57 protons

d.
iron with an atomic number of 57

Answer 1

@matt101

Answer 2

I feel like its A but im not sure

Answer 3

oh wait no I think its b? @matt101

Answer 4

B is correct! This notation distinguishes different isotopes of the same element.

Answer 5

Answer is b, I think.

The description tells you which ISOTOPE of iron is being described.
I’ve looked at a table of isotopes, and I’ve seen that “normal” iron has 26 protons in the nucleus, 30 neutrons in the nucleus (to make a total of 56 “particles” in the nucleus) and 26 electrons outside which help to ensure that it is electrically neutral. By “normal”, I mean that the table says that Iron-56 is 91.66% of the iron you find.
The question refers to iron-57. The table says that this is 2.19% of the iron you find. Iron-57 will have 31 neutrons in the nucleus. Since that, when added to the number of protons – ie 26 - will tell you how much MASS there is in the nucleus which is 57. So, the iron-57 means that it is iron with a mass number of 56 which is being referred to, and this is answer b.

Answer 6

Radio chemical Assaying.
This is the procedure in which the contents of a given sample of a substance are analysed into their atomic/nuclear constituents.
So, in a given sample of iron, presumably drilled from the ground, 91.66% is iron-56, 2.19% is iron-57, and there are a traces of other isotopes of iron.

I think that Radio chemical Assaying was the technique used by Professors Lisa Meitner and Otto Hahn, to establish that they had achieved NUCLEAR FISSION during the earlyish 1900s. Their assaying procedures seemed to reveal that what started out as, say, uranium, ended up being mixed with say, uranium and lead. Some of the uranium had FISSIONED, and lead was a fission product. Hahn was awarded the Nobel prize for their work, with Professor Meitner elbowed out for sexist and racist reasons, it is said.

Assaying is a procedure which is used to establish the contents of a given sample of a material. One ancient, going back to Greek times, use of it was to establish just how much gold was in a so-called gold coin. After all, gold and lead are of similar densities/masses, so how could a trader tell a solid gold coin, from gold mixed with lead ? It may have been ARCHIMEDES who came up with the idea of assaying the coin to find out.

Answer 7

I’ve looked at a copy of a table of isotopes, and iron seems to have 6 of them.
I’ve looked at a copy of the periodic table of the elements from a science data book.
Iron’s ATOMIC number is 26. That means that neutral “normal” iron has 26 protons in the nucleus, surrounded by 26 electrons.
BUT, this does not indicate the actual MASS of an atom or nucleus of iron, since it DOES NOT count the number of neutrons in the nucleus.
The mass of a neutron is similar to that of a proton, and so must be taken into account. (By contrast, the mass of an electrons is several tens/hundreds smaller.)
http://perendis.webs.com

Answer 8

It gives Atomic Mass. This type of notation is generally used in the case of isotopic elements. An element has fixed number of electrons and protons but may have varying number of neutrons which directly effects the mass of the element. So, the correct answer is (b).