Nitrogen (atomic number 7) has a stable isotope (atomic weight 14) and an unstable isotope (atomic weight 15)?
361815
The similarity is the atomic number, as determined by the number of protons. Also the same number of electrons if not ionised.\n\nThe difference is the number of neutrons. Also differences in mass and binding energy per nucleon.\n\nA decay from 15N7 to 15O8 means the number of nucleons remains the same, but it has one more proton and one less neutron.\n\nNeutron decay is as follows:\n\n(n0) -> (p+) + (e-) + (-v)\n\nNeutron -> Proton + Electron + Antineutrino\n\nThis is negative beta decay since it produces a negative electron (which will almost certainly orbit the nucleus which now has an extra proton).\n\nThe atomic decay is:\n\n15N7 -> 15O8 + (e-) + (-v)\n\nSee the link for the appropriate notation
709780
A substance whose atoms all have the same number of protons. Neutron numbers may vary (these are called "isotopes"). In a neutral (non-charged) atom, the number of electrons equals the number of protons.
937526
If the reaction would "go" it is written: 3H2 + N2 = 2 (NH3)\nFill in the atomic masses of H = 1.00797 and N = 14.0067:\n[3 x 2 x (1.00797)] +[ 2 x (14.0067)]  = 2 x (14.0067) x 3 x (1.00797) = 34.06122\nThis is the stochiometric ratio of elements needed. You have 2.04 gm of H2, so multiply each term by 2.04 / 6.04782 to get:\n2.04 + 9.4492 = 11.4892. In other words, all of the H2 combines with about 9.45 gm of N2 to yield about 11.49 gm of ammonia with about 1.9 gm of N2 left over.
14501
There is a rule that isobars (isotopes of different elements which have the same sum of protons and neutrons) are stable only if there is a distance of at least 2 protons to the next isobar.\n\nI know of no easy way to predict which isobars will be stable and which won't.
864891
The isotopic notation is just the mass number (proton + neutron) before the chemical symbol. Since copper has an atomic number of 29 then the isotopic notation respectively, \n63Cu\n\n65Cu
146528
27=13 protons + 14 neutrons.  For aluminium always have 13 protons (the atomic numbers), otherwise will be another element.  Number of electrons, it is not anion just the alumnium in the metallic state will be the same as atomic number, in this case 13.
575905
It is  1.008 g/mol. for hydrogen atoms\n\nOne hydrogen atom weights on the average 1.67323 * 10^-24 grams.\n\nHydrogen gas contains 2 atoms so it weights 3.4646 *10^-24 grams.\n\nAverage mass is average abundunce of all the isotopes of hydrogen
511807
Simple:\n\nN-16  - beta- ==========> O-16\n\nIn releasing a beta particle, one of the neutrons in the nucleus changes to a proton.  That moves the atomic number up by one, changing the element from nitrogen to oxygen, but does not effect the atomic weight, which remains 16.  So Nitrogen 16 decays into the stable form of Oxygen 16.\n\nEasy, no?
851578
It would be either an isotope or an ion depending on the number of neutrons or electrons in the atom.\nA good example of this for isotopes is hydrogen:\nWhen there is no neutrons it is H1 or just plain hydrogen\nWhen there is 1 neutron it is Deuterium or H2 also called heavy hydrogen\nWhen there is 2 neutrons it is called tritium or H3\n\nIf the only difference is the addition or removal of one or more electrons it is an Ion.
955650
Do you have the percentage abundances of the isotopes?\nE.g. for chlorine, it exists as 2 isotopes, namely Cl-37 and Cl-35.\nCl-37 (with 17 protons and 20 neutrons) has an abundance of 25% with Cl-35 (with 17 protons and 18 neutrons) has an abundance of 75%.\nThus average relative atomic mass of chlorine\n= [(25/100) x 37] + [(75/100) x 35]\n= 35.5\n\nHope this helps :)
172336
I believe the answer is Osmium. He is asking for number of neutrons, not number of protons. Take the atomic mass, (Os = 190.23) And subtract the number of protons it has (Os = 76), giving you an answer of 114.
1098584
Chlorine's mass is not a whole number because of the existence of isotopes of chlorine. Isotopes of chlorine have the same atomic number but with different mass number. The mass of chlorine 35.5 is therefore the average mass of all these isotopes based on each isotope's percent abundance in nature.
838540
Isotopes are atoms with the same amount of protons, but different numbers of neutrons.
891726
atomic mass unit, 1/12 of the mass the carbon 12, the most common carbon isotope. Try a periodic table.\n\n\n**** \n1 atomic mass unit = 1.66053886 × 10-27 kilograms
651393
atomic number increase by one, atomic mass stays the same.  A nutron splits into a + and a -
791445
It's composed of the most common isotope of carbon and hydrogen which is carbon-12 and hydrogen-1.\n\nCarbon-12 has 6 protons, 6 neutrons and 6 electrons.\n\nHydrogen-1 has 1 proton and 1 neutron.\n\nSo...\n\nProtons: (6 + 1) * 6 = 42\nNeutrons 6 * 6 = 36\nElectrons (6 + 1) * 6 = 42
853125
The atomic number of Aluminum is 13 (look at a periodic table). This means 13 protons and 13 electrons (since these are oppositely charged they have to balance each other.) To find the number of neutrons you subtract the number of protons from the atomic mass (the atomic mass is 27). So 27-13= 14 neutrons