Potassium compounds emit a lilac or violet flame color when burned. It burns in water, just like sodium.Potassium was the first metal to be isolated using electrolysis. Potassium was first purified in 1807 by Cornish chemist Humphry Davy (1778–1829) from caustic potash (KOH) via electrolysis.An overabundance of potassium causes hypercalcemia, which produces similar symptoms. Plants require potassium for many processes, so this element is a nutrient that is readily depleted by crops and must be replenished by fertilizers. Symptoms of hypokalemia include muscle cramps and irregular heartbeat. When not enough potassium is available in the body, a potentially fatal condition called hypokalemia can occur. This is vital for many cellular processes and is the basis for the conduction of nerve impulses and stabilization of blood pressure. Animals use sodium ions and potassium ions to generate electric potentials. The potassium ion is important for all living cells.Pure potassium usually is stored under oil or kerosene because it oxidizes so readily in air and reacts in water to evolve hydrogen, which may be ignited from the heat of the reaction.Pure potassium is a lightweight silvery metal that is soft enough to cut with a knife. Although the metal appears silver when it's fresh, it tarnishes so quickly that it normally appears dull gray.It is formed by supernovas via the R-process and occurs on Earth dissolved in seawater and in ionic salts. Because of its high reactivity, potassium is not found free in nature.Potassium is one of the alkali metals, which means it is a highly reactive metal with a valence of 1. ![]() This means the atomic number of potassium is 19 and each potassium atom has 19 protons. Appearance: Potassium is a solid, silvery-gray metal at room temperature.Please use the search box to find pages / postings on specific themes. In Annie's case she not only provided repeated answers with the same examples, bit was consistent in the way she interpreted plus and minus symbols across a range of different examples, suggested this was a stable aspect of her thinking. When a student repeats the same answer at different times it suggests the response reflects a stable aspect of their underlying ' cognitive structure'. Students often present incorrect responses in class (or in interviews with researchers) and sometimes these are simply slips of the tongue or memory, or 'romanced' answer guessed to provide some kind of answer. K + referred to the potassium atom (2.8.8.1), not the cation (2.8.8)į – referred to the fluorine atom (2.7), not the fluoride anion (2.8) Represents fluorine which has one, it has an outer shell of seven which has one less electron. Potassium atom, and it's got one extra electron over a full shellĪnd that's what the plus means, one more electron than it wants? Potassium…An atom that has an extra electron. ![]() Right, okay, so this one here where it's got a K and a plus, what does that represent? Annie was shown, and asked about, a sequence of images representing atoms, molecules and other sub-microscopic structures of the kinds commonly used in chemistry teaching.Įarlier in her interview she had suggested that plus and minus signs represent the charges on neutral atoms when discussing the Na-plus (Na +) and Cl-minus (Cl –) symbols, suggesting an alternative conception of electrical charge in relation to atoms, ions and molecules She gave similar interpretations in the case of K-pus (K +) and F-minus (F –): She was interviewed near the start of her college 'A level' course (equivalent to Y12 of the English school system). Annie was a participant in the Understanding Chemical Bonding project.
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