Its name comes from the Greek words "oxus," which means acid, and "gennan," which means generate. For Sulphur: Number of protons = 16. So for an atom to be known as an oxygen atom, it must have 8 protons. Mass number = Number of Protons + Number of neutrons = 16 + 16 = 32. density of oxygen is equal to 1.429 kg/m³; at 0°C (32°F or 273.15K) at standard atmospheric pressure.In Imperial or US customary measurement system, the density is equal to 0.08921 pound per cubic foot [lb/ft³], or 0.000826 ounce per cubic inch [oz/inch³] . To understand why knowing oxygen’s molar mass is important, we first have to understand what molar mass is and how it relates to doing calculations in chemistry.. What Is Molar Mass? Water is ~11% hydrogen by mass but ~67% hydrogen by atomic percent, and these numbers along with the complementary % numbers for oxygen in water, are the largest contributors to overall mass and atomic composition figures. For example, if an atom has 9 protons, it will no longer be oxygen, but will instead be Fluorine. Oxygen accounts for nearly half of the mass of the earth's crust, two thirds of the mass of the human body and nine tenths of the mass of water. Under ordinary conditions, it can exist as a pure element in the form of oxygen gas (O 2) and also ozone (O 3).Here is a collection of facts about this essential element. 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 … 16 - 8 = 8. Its symbol is O. Similar Questions. Consider a sphere of radius R with charge density distributed as ρ(r) = kr for r ≤ R = 0 for r >R . ››More information on molar mass and molecular weight. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images. Oxygen has an atomic number of eight, and the molar mass of oxygen is approximately 15.9994. Oxygen has an atomic number of 8 and is classified as a non-metal. This atom will have 10 neutrons as 18 - 8 = 10 Since both of these elements are diatomic in air - O 2 and N 2, the molar mass of oxygen gas is 32 g/mol and the molar mass of nitrogen gas is 28 g/mol. Number of electrons = 16. Oxygen is one of the most abundant elements on planet Earth and in the universe. The atomic mass of oxygen is 15.9994 atomic mass units. Hence mass number for Oxygen is 16. Hence Mass number for Sulphur is 32. Oxygen was discovered in 1774 by Joseph Priestly, according to Chemical Elements. Oxygen is the element with atomic number 8 and element symbol O. Oxygen exists in isotopic form and has an isotope with mass number 18. Large amounts of oxygen can be extracted from liquefied air through a process known as fractional distillation. The atomic number for oxygen is 8, so the atom has 8 electrons and 8 protons. About Oxygen; Oxygen weighs 0.001429 gram per cubic centimeter or 1.429 kilogram per cubic meter, i.e. Oxygen has a molar mass of 15.9994 g/mol and nitrogen has a molar mass of 14.0067 g/mol. Oxygen has an atomic number of 8. Protons and neutrons are found in the nucleus, so the number of neutrons is found by subtracting the proton number from the mass number I.e. Element Oxygen (O), Group 16, Atomic Number 8, p-block, Mass 15.999.