The electrical resistivity of chromium at 20 ☌ is 125 nanoohm- meters.Ĭhromium has a high specular reflection in comparison to other transition metals. The boiling point of 2671 ☌ (4840 ☏), however, is comparatively lower, having the third lowest boiling point out of the Period 4 transition metals alone behind manganese and zinc. However, it still has the second highest melting point out of all the Period 4 elements, being topped by vanadium by 3 ☌ (5 ☏) at 1910 ☌ (3470 ☏).
Chromium is highly resistant to tarnishing, which makes it useful as a metal that preserves its outermost layer from corroding, unlike other metals such as copper, magnesium, and aluminium.Ĭhromium has a melting point of 1907 ☌ (3465 ☏), which is relatively low compared to the majority of transition metals. Its Mohs hardness is 8.5, which means that it can scratch samples of quartz and topaz, but can be scratched by corundum. Bulk Ĭhromium is extremely hard, and is the third hardest element behind carbon ( diamond) and boron. Chromium(VI) is a strong oxidising agent in contrast to the molybdenum(VI) and tungsten(VI) oxides.
#Is crx 4 chrome real series
(Similar promotions happen for every transition metal atom but one, palladium.) Ĭhromium is the first element in the 3d series where the 3d electrons start to sink into the nucleus they thus contribute less to metallic bonding, and hence the melting and boiling points and the enthalpy of atomisation of chromium are lower than those of the preceding element vanadium. This lowers the energetic cost of promotion and increases the energy released by it, so that the promotion becomes energetically feasible and one or even two electrons are always promoted to the 4s subshell. However, in the 3d transition metals, the energy gap between the 3d and the next-higher 4s subshell is very small, and because the 3d subshell is more compact than the 4s subshell, inter-electron repulsion is smaller between 4s electrons than between 3d electrons. In the previous elements, the energetic cost of promoting an electron to the next higher energy level is too great to compensate for that released by lessening inter-electronic repulsion. This occurs because electrons in the same orbital repel each other due to their like charges. This occurs again later in the periodic table with other elements and their electron configurations, such as copper, niobium, and molybdenum. It is also the first element in the periodic table whose ground-state electron configuration violates the Aufbau principle. Physical properties Atomic Ĭhromium is the fourth transition metal found on the periodic table, and has an electron configuration of 3d 5 4s 1.
A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. The name of the element is derived from the Greek word χρῶμα, chrōma, meaning color, because many chromium compounds are intensely colored.Ĭhromium metal is valued for its high corrosion resistance and hardness. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared light. Chromium is also highly valued as a metal that is able to be highly polished while resisting tarnishing. Chromium is the main additive in stainless steel, to which it adds anti-corrosive properties. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium is a chemical element with the symbol Cr and atomic number 24.