Antimony, Sb, has the atomic number 51. The atomic number is the number of protons in the nuclei of all antimony atoms, so Sb atoms have 51 protons. In a neutral atom, the number of protons equals the number of electrons. So Sb atoms also have 51 electrons. Antimony-121 is an isotope of antimony with a mass number of 121. From the mass number, we can subtract the number of protons and get the number of neutrons in the atoms of the 121Sb isotope, which is 121-51 = 70 neutrons.
The isotope 121Sn has 50 protons, 50 electrons and 71 neutrons.
53 protons 68 neutrons
Antimony (symbol Sb) has three isotopes: 121Sb, 123Sb, and 125Sb. The 121 isotope has 70 neutrons, and the 123 isotope has 72 neutrons. The 125 isotope isn't stable and will decay, but it has 74 neutrons.
121.760
121 neutrons.
80
No element with 121 electrons has yet been discovered (as of December 2016).
Antimony-121 at 57.25%, the rest is Antimony-123
The atomic mass of an element is the weighted average of the masses of its isotopes. You know that: Antimony-121 has a mass of 120.9038 u, x% abundance Antimony-123 has a mass of 122.9042 u, y% abundance There are only 2 isotopes for antimony and their percent abundances should add up to 100%. In other words: x% + y% = 100% y = 1-x (percentages written as decimals) So, now let's put everything together. In order to calculate the atomic mass, multiply the percent abundance of an isotope by its atomic mass; then add the product of all the isotopes: (Atomic Mass of Antimony-121)(Percent Abundance of Antimony-121) + (Atomic Mass of Antimony-123)(Percent Abundance of Antimony-123) = Atomic Mass of Element Antimony (120.9038 amu)(x) + (122.9042 amu)(y) = 121.760 amu Replacing 1-x for y gives: (120.9038 amu)(x) + (122.9042 amu)(1-x) = 121.760 amu Solve for x: 120.9038x + 122.9042 -122.9042x = 121.760 amu -2.0040x = -1.1442 x = 0.57096 = 57.096% Solve for y: y = 1 - x y = 1 - 0.57096 = 0.42904 = 42.904%
Antimony (symbol Sb) has three isotopes: 121Sb, 123Sb, and 125Sb. The 121 isotope has 70 neutrons, and the 123 isotope has 72 neutrons. The 125 isotope isn't stable and will decay, but it has 74 neutrons.
121 121 121 121
121.760
121 km = 121 000 m
The factors of 121 are: 1, 11, 121
121 pounds = 8.64285714 stones 121 kilograms = 19.0542384 stones
121 verses that is 121 stanzas
121 days = about 4 months.
3 numbers are factors of 121. They are 1, 11 and 121 itself.
You look up antimony. You discover its symbol is SB. You look on your periodic table. You come to the symbol SB. You see that it is number 51. You know that is also the number of protons in the atom. You know that 122 is the atomic weight. You know that the Atomic Weight mainly comes from the weight of the neutrons and protons. You know that when you have the atomic weight you can subtract the atomic number from the atomic weight and get the number of neutrons.