The Standard English unit is pounds mass per cubic foot ( lbm/ft 3).Įlectron Affinity and Electronegativity of ChromiumĮlectron Affinity of Chromium is 64.3 kJ/mol. The standard SI unit is kilograms per cubic meter ( kg/m 3). In other words, the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance. It is an intensive property, which is mathematically defined as mass divided by volume: Typical densities of various substances at atmospheric pressure.ĭensity is defined as the mass per unit volume. See also: Mass Number Density of Chromium For 63Cu, the atomic mass is less than 63, so this must be the dominant factor. A nucleus with greater binding energy has lower total energy, and therefore a lower mass according to Einstein’s mass-energy equivalence relation E = mc 2. The nuclear binding energy varies between nuclei.This increases the mass of nuclei with more neutrons than protons relative to the atomic mass unit scale based on 12C with equal numbers of protons and neutrons. The neutron is slightly heavier than the proton.There are two reasons for the difference between mass number and isotopic mass, known as the mass defect: For example, 63Cu (29 protons and 34 neutrons) has a mass number of 63, and an isotopic mass in its nuclear ground state is 62.91367 u. The isotopic mass usually differs for other isotopes and is usually within 0.1 u of the mass number. One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol.įor 12C, the atomic mass is exactly 12u since the atomic mass unit is defined from it. One atomic mass unit is equal to 1.66 x 10 -24 grams. The unit of measure for mass is the atomic mass unit (amu). Note that, each element may contain more isotopes, therefore this resulting atomic mass is calculated from naturally-occuring isotopes and their abundance.
See also: Properties of Chromium Atomic Mass of Chromium A major development was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel.Ĭhromium – Properties Element Chromium Atomic Number 24 Symbol Cr Element Category Transition Metal Phase at STP Solid Atomic Mass 51.9961 Density at STP 7.14 Electron Configuration 3d5 4s1 Possible Oxidation States +2,3,6 Electron Affinity 64.3 Electronegativity 1.66 1st Ionization Energy 6.7666 Year of Discovery 1797 Discoverer Vauquelin Thermal properties Melting Point 1907 Boiling Point 2671 Thermal Conductivity 93.7 Specific Heat 0.45 Heat of Fusion 16.9 Heat of Vaporization 344.3
The chemical symbol for Chromium is Cr.Ĭhromium is a steely-grey, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point. Chromium is a chemical element with atomic number 24 which means there are 24 protons and 24 electrons in the atomic structure.
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