A mass number of 23 means … There are 2 isotopes of sodium, Na-22 and Na-23. It is considered a monoisotopic element and it has a standard atomic weight of 22.989 769 28 (2).Sodium has two radioactive cosmogenic … no of atoms in Na =2 * avocadro no= 2 * 6.03 *10^23 =12.06 *10^23 atom 3) than we have to multiply the … An atomic number of 11 means this atom will have 11 protons. Mass numbers of typical isotopes of Sodium are 23. ››More information on molar mass and molecular weight. How do you think about the answers? 0 0. 1 decade ago. In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together. Anonymous. The total number of neutrons in the nucleus of an atom is called the neutron number of the atom and is given the symbol N. Neutron number plus atomic number equals atomic mass number: N+Z=A. Table \(\PageIndex{1}\): Atoms of the First Six Elements; Name Symbol Atomic Number (Z) aprox. The chemical symbol for Sodium is Na.. Atomic Mass of Sodium. 23g per mol (23 amu per each) 0 0. Get your answers by … The Mass Number of an element is equal to the protons added to the neutrons. Consider the table below, which shows data from the first six elements of the periodic table. The mass number. X. No of moles of Na = mass of Sodium/molar mass 1) frist we have to divide mass of Na w.r.t molar mass of Na #) molar mass of Na =23 gm/mol #) no of moles of Na =46/23 =2mol 2) than we easily get the no of moless. Note that, each element may contain more isotopes, therefore this resulting atomic mass … The element Sodium has an atomic number of 11 and an average atomic mass of 22.98 which makes the mass number 23. 1 decade ago. Still have questions? You can sign in to vote the answer. The sum of neutrons and protons, the massive nuclear particles, gives the mass number, with which we often label the elemental symbol as a left hand superscript. Sign in. Mass number is protons plus neutrons and can be different for different isotopes. It has an atomic mass of 22.9, which is often rounded up to 23 to accurately determine the number of neutrons in the element. Sodium is a metallic element on the periodic table with an atomic number of 11 and an atomic mass of 22.98 amu. Sodium (Na) Sodium has an atomic number of 11 and a mass of about 23g. The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Atomic Number of Sodium. There are 21 recognized isotopes of sodium (11 Na), ranging from 18 Na to 39 Na and two isomers (22m Na and 24m Na). Mass Number of Sodium. Sodium was discovered by Sir Humphrey Davy in 1807. Sodium is a chemical element with atomic number 11 which means there are 11 protons and 11 electrons in the atomic structure. 23 Na is the only stable (and the only primordial) isotope. Atomic mass of Sodium is 22.9897 u. Name: Sodium Symbol: Na Atomic Number: 11 Atomic Mass: 22.98977 amu Melting Point: 97.72 °C (370.87 K, 207.9 °F) Boiling Point: 883 °C (1156 K, 1621 °F) Number of Protons/Electrons: 11 Number of Neutrons: 12 Classification: Alkali Metal Crystal Structure: Cubic Density @ 293 K: 0.971 g/cm 3 Color: silvery Atomic Structure But the number of #"nucular protons"#, i.e. The element sodium has 12 neutrons. 0 0. We know that the atomic number of sodium is 11. The most common (in fact, pretty much 100%) is Na-23 which has a mass number of 23 (11 protons, 12 neutrons). #Z#, UNEQUIVOCALLY identifies the atom; #Z=11# for sodium, #Z=10# for neon; #Z=12# for magnesium. The element also has an atomic number of 11, meaning that it has 11 electrons and 11 protons. Therefore . Anonymous. is given at the top left of the element's symbol, for example, sodium has a mass number of 23. This atomic mass is calculated by adding together the number of protons and neutrons present in the atom's nucleus.