h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

“Each element is distinguished from the number of protons in the nucleus.”

Should be:
“Each element is distinguished from any other element by the number of protons in the nucleus.”

“Ions are atoms which have lost or gained an electron, thus giving them a chage value.”

“Atomic ions are ions which have lost or gained one or more electrons, thus giving the ion an overall positive or negative charge.”

“Molecules made up of mixtures of metals and non-metals use this to create bonds based on the fact that opposing charges attract one another.”

“A molecule is group of two or more atoms held together by covalent bonds.”
“A covalent bond involves the sharing of electrons between atoms.”

[note, i.e., oxygen and hydrogen normally form molecules of two atoms of the same element and a water molecule formed from two non-metals, hydrogen and oxygen]

“There are 116 known elements all displayed within the periodic table.”

As of November 2011, 118 elements have been identified, the latest being ununseptium in 2010.[1] Of the 118 known elements, only the first 98 are known to occur naturally on Earth; 80 of them are stable, while the others are radioactive, decaying into lighter elements over various timescales from fractions of a second to billions of years.
http://en.wikipedia.org/wiki/Chemical_element

Page turner:

Entry: Atoms and Isotopes: Pre-university Level - A87762171
Author: mikeyc0312 - U612358

Are you still working on this, mikeyc0312?

GB

I'm still on it, GB. There hasn't been many suggestions recently, however.

I think this Entry explains thigns very well.

AE Hill made quite a few suggestions five weeks ago. None of these appear to have been acted on. If you don't like the suggestions, please state this and we can discuss them.

With a subject about science it is important to be factual.
It can be a challenge to be factual and not get too deep into the subject.
Even some of my suggestions need editing.

This entry has the potential to be very interesting to many people.

What would you like to do with this entry?
It could go in many directions.
What intentions do you have?

I posted:
“Atomic ions are ions which have lost or gained one or more electrons, thus giving the ion an overall positive or negative charge.”

I should have posted:

“Atomic ions are Atoms which have lost or gained one or more electrons, thus giving the ion an overall positive or negative charge.”

It is not necessary to use my words, but if you want to correct the problem in your own words, be factual.

What is not said here is that there are molecular ions. So to define "ions" correctly and simply, you can exclude molecular ions.

How is this coming along?
This entry is receiving positive feedback, and appears that only a couple of minor tweaks are outstanding at the moment. I'd hate to see it stall.

<BB<

Could I suggest "Atoms and Isotopes - A beginners guide" as a title

A brief definition of a metal may also help - e.g. - An atom with one, two or three electrons in the outer shell which tend to lose electrons and form positive ions.

tucuxii: The name change is an interesting idea, but your definition of a metal is far too simplistic as it doesn't cover the majority of transition metals, for example gold is completely inert and doesn't form ions, positive or otherwise.

I have now updated the entry to include AE Hill's suggestions. Anything else that needs changing, just tell me.

How is this coming along? Does anyone have any more comments?

<BB<

First section,

"...over 100 known elements, 98 0f which occur naturally..."

Actually there are only 91 naturally occurring chemical elements, Uranium, generally considered the heaviest naturally occurring chemical element is element 92 and technetium, element 44, is in an island of instability, has no known stable isotopes and does not occur in nature.

There should be a comma after "Atoms are neutral..." and the comma before ", and therefore" in the same sentence should be omitted.

You might insert a sentence, "Periodic law is based on ground states of atoms." after the passage on ions.




Second section, Isotopes

To be a little more pedantic, "because the neutrons change" should read, "because the number of neutrons changes,"




Fourth section, Molar mass

The mole is a fundamental constant that also appears in sub-atomic physics and quantum mechanics.

(I'd recommend carefully re-evaluating this section, not placing a sole reliance on Wikipedia as a source. Their writing and material in the relevant articles on the mole and Avogadro's number are considerably below their usual standard.)




Fifth section, Measuring relative atomic mass

1. I'd spell 'spectrometer' in full.

2. The charge on an electron is negative, bombarding with electrons
will induce a negative charge.

A positive charge is usually induced by means of heating the specimen to drive off electrons.

3. & 4. Omit the term 'positive'.

4.I would make that 'a magnetic field' rather than 'the magnetic field'. Saying 'the' assumes the reader already knows the mechanics.




Sixth and seventh sections, Relative molecular mass & Relative formula mass.

These are crystalline lattices, not ionic compounds. Silicon dioxide is covalent, not ionic. The monomer of a crystal lattice or polymer is usually treated as the molecule.

Say 'quartz' rather than 'sand'. Sand can be comprised of any of a number minerals, is usually a mixture and may not contain any silica at all.

http://wiki.answers.com/Q/Which_bond_has_a_crystalline_structure

http://physicsmathforums.com/showthread.php?t=994

This is going a little beyond the pre-university level.

Just to note electron impact ionisation is a cheap means of generating positive ions. It also tends to fragment molecules. Basically a relatively high energy electron beam is passed through the vapour. Some of the electrons will penetrate the atom or molecule and knock out an electron. It will still have sufficient energy not to be captured:
http://en.wikipedia.org/wiki/Electron_ionization

Everything else ITIWSB mentions seems fine at first sight. I had a quick look at the actual article and there were a few things that could be tightened up (e.g. use of mass and mass number, use of accepted versus defined or measured).

Entry: Atoms and Isotopes: Pre-university Level - A87762171
Author: mikeyc0312 - U612358
Original Entry: A87722012 Atoms and isotopes - A level Standard
Original Author: Nicki - U871201

I've not seen Mikey since February. Are you still around?

<BB<

Seeing inside of an atom:
http://www.foxnews.com/science/2013/05/28/amazing-first-ever-photograph-inside-hydrogen-atom/

I should have made "The monomer of a crystal lattice or polymer is usually treated as the molecule." extend from 'molecule...' to read, "...with inorganic compounds, eg, those which do not contain complex carbon structures."

Whew!

https://www.khanacademy.org/science/healthcare-and-medicine/lab-values/v/the-mole-and-avogadro-s-number

I'd say this looks like a pretty good article on Avogadro's number and the mole.

It took some doing finding it between the beggar's burdica rabble and the usual Googleplethora of irrelevancies.