When an element has a ' minus' after it, it is an ion (anion).
This means that it has gained an electron.
When an element has a ' plus' after it, it is an ion (cation).
This means that it has lost an electron.
Taking oxygen as an example. In the Periodic Table Its atomic number is '8' and its atomic mass is '16'.
Ths '8' tells us that it has '8' protons and '8' electrons, when it is the neutral atom.
The '16' tells us that it has '8' protons and '8' neutrons (8+8=16)
When oxygen is decribed as 'O2-' (NB this is NOT the diatomic molecule but the ionic charge of 2 minuses on an atom of oxygen), it means that the atom still has 8 protons but has gained 2 electrons making 10 electrons in total. '8' positives (8+) against '10' negatives (10-) making a net difference of '2' negatives (2-). Hence in formula it is described as 'O2-'
Taking sodium as another example. In the Periodic Table Its atomic number is '11' and its atomic mass is '23'.
Ths '11' tells us that it has '11' protons and '11' electrons, when it is the neutral atom.
The '23' tells us that it has '11' protons and '12' neutrons (11+12=23)
When sodium is decribed as 'Na+' (NB this is NOT the diatomic molecule but the ionic charge of 1 plus on an atom of sodium), it means that the atom still has 11 protons but has lost 1 electron making 10 electrons in total. '11' positives (11+) against '10' negatives (10-) making a net difference of '1' positive (+). Hence in formula it is described as 'Na+'
2007-10-26 08:55:46
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answer #1
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answered by lenpol7 7
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It means it has gained an electron and is negatively charged (-) Ion (As in Cl- that reacts with Na+ Ion to become Sodium Chloride (NaCl).
Where the Na has lost an electron and become positively charged as Na+ and the electron has been taken by the Cl to become Cl-. The process is called 'Ionic' or 'Electro-valent' bonding.
The atomic number of an element (the number directly above the element symbol in the table of elements) tells you how many Protons are in the atom. Then, for a stable atom...(not an Ion)...the number of electrons is equal to the atomic number.
Directly below the Symbol and name, is another number. This is the Atomic Mass and, if you subtract the atomic number from the atomic mass, you'll have the number of Neutrons. e.g. Potassium (K). The atomic number is 19..so, .it has 19 Protons. (and therefore 19 electrons if not ionised).
Its atomic mass No. is 39.
39 - 19 = 20 = 20 Neutrons....19 protons, 19 electrons and 20 neutrons make up the main components of the Potassium atom. (There are other smaller sub-atomic particles not given in the general Table of elements).
2007-10-25 14:33:19
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answer #2
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answered by Norrie 7
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the answer can be found in the periodic table. The big letters are atomic symbols. They are the element's "name". The integer (whole) numbers are the number of protons in the nucleus. It is also the number of electrons. The number with decimal points is the atomic weight (or atomic mass). This is the weight of the atom, but electrons have no weight, so the number is the weight of the protons and neutrons. Because protons and neutrons weigh the same, then:
# electrons = atomic number
# protons = atomic number
# neutrons = atomic weight - atomic number (round to whole number)
Elements with a "-" or "+" signs mean there are not as many electrons as protons. If an element is negative, it means there are more electrons than protons. If the element is positive, there are less electrons than protons.
To find the number of electrons, reverse the sign and add this to the atomic number. For example an element with a sign of -2 would have 2 more electrons than protons. In other words, add 2 to the atomic number.
An element can have different numbers of electrons and neutrons, but all elelents all have exactly the same number of protons.
2007-10-25 09:09:43
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answer #3
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answered by Roger S 7
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a million. there's no element which could have 12 protons and 24 neutrons. i assume you recommend it has a mass variety of 24, wherein case the element could be magnesium (12 protons, 12 neutrons). 2. Nitrogen has 5 valence electrons (purely count type from the previous noble gasoline) 3. To have an entire valence shell, nitrogen could desire to settle for 3 greater electrons (8 entire) 4. Protons = atomic type = 7 for N Electrons = comparable as protons = 7 for N Neutrons = mass type - protons = 7 for N-14 5. factors that variety in uncomplicated terms in the variety of neutrons are referred to as "isotopes" 6. Charged factors are primary as "ions" 7. Beryllium has 2 valence electrons, and in case you get rid of an electron it turns right into a actually charged ion, or "cation." it could have a 2+ fee in case you get rid of the two valence electrons.
2016-11-09 11:11:03
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answer #4
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answered by ? 4
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well its quite simple really , ifA = b_ c then you multiply it by $¬+=355% and the protons < >than the neutrons and the electron is still dissipating at >< more than 24 voltaires then isuggest you unplug your hairdryer and return it to asda
2007-10-25 09:07:53
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answer #5
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answered by Anonymous
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means its negatively charged has extra electron
2007-10-25 08:56:22
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answer #6
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answered by Anonymous
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