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A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
NaK containing 40% to 90% potassium by mass is liquid at room temperature.The eutectic mixture consists of 77% potassium and 23% sodium by mass (NaK-77), and it is a liquid from −12.6 to 785 °C (9.3 to 1,445.0 °F), and has a density of 0.866 g/cm 3 at 21 °C (70 °F) and 0.855 g/cm 3 at 100 °C (212 °F), making it less dense than water. [3]
In thermodynamics, an activity coefficient is a factor used to account for deviation of a mixture of chemical substances from ideal behaviour. [1] In an ideal mixture, the microscopic interactions between each pair of chemical species are the same (or macroscopically equivalent, the enthalpy change of solution and volume variation in mixing is zero) and, as a result, properties of the mixtures ...
[10]: 322 Ternary alkali metal halide oxides, such as Na 3 ClO, K 3 BrO (yellow), Na 4 Br 2 O, Na 4 I 2 O, and K 4 Br 2 O, are also known. [ 10 ] : 83 The polyhalides are rather unstable, although those of rubidium and caesium are greatly stabilised by the feeble polarising power of these extremely large cations.
The difference is attributed to the similarity in size between nitrate (NO − 3) and carbonate (CO 2− 3) ions and the fact that the potassium ion (K +) is larger than sodium (Na +) and calcium (Ca 2+) ions. [34] In the room-temperature structure of potassium nitrate, each potassium ion is surrounded by 6 nitrate ions.
Legend: Na - melting point of pure sodium, K - melting point of pure potassium, E - eutectic point, P - peritectic point, blue line - melting point of eutectic mixture, black line - melting point of compound Na 2 K, red line - melting point of surplus
The temperature difference between the two regions gives rise to a certain sodium activity differential, the sodium expands almost isothermally. Since the beta alumina electrolyte does not conduct electrons favourably the expansion causes sodium ions across the membrane and the electrons through an external circuit.
Cation–π interaction between benzene and a sodium cation. Cation–π interaction is a noncovalent molecular interaction between the face of an electron-rich π system (e.g. benzene, ethylene, acetylene) and an adjacent cation (e.g. Li +, Na +). This interaction is an example of noncovalent bonding between a monopole (cation) and a ...