In general, there are two defining numbers for all elements and their isotopes: the mass number, and the atomic number. These are usually denoted as follows when an element is written:
AZ X
where A is the mass number, Z is the atomic number, and X is the symbol for the element in question (note that the A and Z would normally be aligned, not offset). The mass number, A, is the sum of the protons and neutrons in the element. The atomic number, Z, is the number of protons only. On the Periodic Table, elements are arranged by atomic number. In this case we see that Carbon is element 6, and so it had 6 protons. The number of neutrons alone can be easily calculated by subtracting the atomic number from the mass number, so that
N=A-Z
where N is the number of neutrons. The number of electrons in a given element, isotope, or ion, can be easily determined as well. In neutral isotopes, the number of negatively-charged electrons must balance the number of positively-charged protons. Since the number of protons is given to us by the atomic number Z, this must also be the number of electrons. In ions, the plus or minus charge denoted tells us the overall charge of the species in question, and thus the lack or excess of electrons. A species with a +2 charge would have two less electrons than expected, while a -1 charge would mean one excess electron.
You add up the mass of the protons, neutrons, and electrons. Protons and Neutrons having an atomic mass of 1, and electrons having an atomic mass of roughly 1/1800.
Find the atomic number. That tells you the number of protons and electrons (in a neutral atom). Then find the atomic weight. The number of protons plus the number of neutrons will equal the atomic weight. So if you know the wt. just subtract the number of protons and you will have the number of neutrons.
The term atomic mass is used only for isotopes; for chemical elements the term atomic weight is recommended.But atomic masses and atomic weights include also all electrons.
C 14 and C 12 are both isotopes of carbon. Since they are the same element, both of these isotopes have the same number of neutrons. However, C 12 has 6 neutrons and is stable whereas C 14 has 8 neutrons and is radioactive.
Isotopes of an element have a different number of neutrons. For example Uranium-235 and Uranium-238 look chemically identical but 238U atom is slightly more massive due to the three extra neutrons.
Oxigen has 8 protons; natural isotopes have 8, 9 an 10 neutrons.
You add up the mass of the protons, neutrons, and electrons. Protons and Neutrons having an atomic mass of 1, and electrons having an atomic mass of roughly 1/1800.
Find the atomic number. That tells you the number of protons and electrons (in a neutral atom). Then find the atomic weight. The number of protons plus the number of neutrons will equal the atomic weight. So if you know the wt. just subtract the number of protons and you will have the number of neutrons.
The term atomic mass is used only for isotopes; for chemical elements the term atomic weight is recommended.But atomic masses and atomic weights include also all electrons.
157; you figure that out by taking the atomic mass (259) and subtract it by the # of protons (102) and the answer is the # of neutrons. ( the atomic #, # of protons, and # of electrons are always the same # 102 ). But each isotope of nobelium has a different number of neutrons, depending on the atomic mass.
Let the N be the atomic No. and M be the mass No.The No. of Electrons=No. of Protons=NThe No. of Neutrons=M-N
I don't want to do your homework for you. Here's how you figure it out: Protons = atomic number Neutrons = atomic mass - atomic number Electrons = atomic number + ionization
6 of each in a neutral (non-ion) atom. The carbon atom contains 6 protons. The number of electrons in any element can vary. These atoms are called ions, where the atoms may lose or gain electrons.
Every chlorine atom has 17 protons; 17 is the atomic number of chlorine. However, chlorine has two isotopes that are stable against radioactive decay. These have mass numbers of 35 and 37, which have 18 and 20 neutrons respectively.
The simplest way to figure this out is as following: the atomic number of sodium is 11, which gives you the number of protons. The number of electrons = the number of protons. The number of neutrons is the atomic weight (22.98 in this case) rounded minus the number of protons. Therefore sodium has 11 protons, 11 electrons, and 12 neutrons. Hope this helps! :)
I-125 contains 73 neutrons. To calculate the number of protons, electrons, and neutrons in an uncharged isotope, follow these rules: Protons = atomic number Electrons = protons = atomic number Neutrons = atomic mass - protons Iodine is number 53 on the periodic table, so its atomic number is 53. It has 53 protons and 53 electrons. This particular isotope of iodine is I-125. So, it has 125-53=72 neutrons.
C 14 and C 12 are both isotopes of carbon. Since they are the same element, both of these isotopes have the same number of neutrons. However, C 12 has 6 neutrons and is stable whereas C 14 has 8 neutrons and is radioactive.