monatomic ion

(noun)

An ion made of only one atom, for example Cl-.

Related Terms

Examples of monatomic ion in the following topics:

  • Electron Configuration of Cations and Anions

    • These charged atoms are known as ions.
    • Monatomic ions are formed by the addition or removal of electrons from an atom's valence shell.
    • Having gained a positive charge, the sodium ion is called a cation.
    • Polyatomic and molecular ions are often created by the addition or removal of elemental ions such as H+ in neutral molecules.
    • The two notations are therefore exchangeable for monatomic ions, but the Roman numerals cannot be applied to polyatomic ions.

  • Formulas of Ionic Compounds

    • Its ionic formula is written as CaCl2, the neutral combination of these ions.
    • Polyatomic ions are a set of covalently bonded atoms that have an overall charge, making them an ion.
    • For example, the hydroxide ion has the formula OH-1.
    • When creating ionic compounds with these polyatomic ions, treat them the same way as typical monatomic ions (only one atom).
    • This video shows you how monoatomic ions get their charge, and how to quickly find the charge of ions by looking at the periodic table.

  • Salts that Produce Basic Solutions

    • As such, salts are composed of cations (positively charged ions) and anions (negative ions), and in their unsolvated, solid forms, they are electrically neutral (without a net charge).
    • The component ions in a salt can be inorganic; examples include chloride (Cl−), the organic acetate (CH3COO−), and monatomic fluoride (F−), as well as polyatomic ions such as sulfate (SO42−).
    • The bicarbonate ion is the conjugate base of carbonic acid, a weak acid.
    • But because HCl is a strong acid, the Cl- ion is not basic in solution, and it isn't capable of deprotonating water.
    • Because the bicarbonate ion is the conjugate base of carbonic acid, a weak acid, sodium bicarbonate will yield a basic solution in water.

  • Ion-Dipole Force

    • The ion-dipole force is an intermolecular attraction between an ion and a polar molecule.
    • However, ion-dipole forces involve ions instead of solely polar molecules.
    • Ion-dipole forces are stronger than dipole interactions because the charge of any ion is much greater than the charge of a dipole; the strength of the ion-dipole force is proportionate to ion charge.
    • An ion-induced dipole force occurs when an ion interacts with a non-polar molecule.
    • Ion-dipole forces are generated between polar water molecules and a sodium ion.

  • Constant Pressure

    • $U = \frac{3}{2}NkT$ for a monatomic gas, we get $\Delta U = \frac{3}{2} Nk \Delta T$
    • $Q = \frac{5}{2} N k \Delta T$ for monatomic gas in an isobaric process.
    • $c_P = \frac{5}{2} kN_A = \frac{5}{2} R$ for a monatomic gas.

  • Internal Energy of an Ideal Gas

    • A monatomic gas is one in which atoms are not bound to each other.
    • Note that there are three degrees of freedom in monatomic gases: translation in x, y and z directions.
    • Helium, like other noble gases, is a monatomic gas, which often can be described by the ideal gas law.

  • The Noble Gases (Group 18)

    • Noble gases are the six chemical elements of Group 18 of the periodic table, being monatomic and (with very limited exceptions) inert.
    • These gases all have similar properties under standard conditions: they are all odorless, colorless, monatomic gases with very low chemical reactivity.
    • In the case of Neon (Ne), for example, both the n = 1 and n = 2 shells are complete and therefore it is a stable monatomic gas under ambient conditions.
    • They are all monatomic gases under standard conditions, including those with larger atomic masses than many other elements that are solids under standard conditions.

  • Lewis Structures for Polyatomic Ions

    • Lewis structures for polyatomic ions are drawn by the same methods that we have already learned.
    • When counting electrons, negative ions should have extra electrons placed in their Lewis structures; positive ions should have fewer electrons than an uncharged molecule.
    • Negative ions follow the same procedure.
    • The chlorite ion, ClO2–, contains 19 (7 from the Cl and 6 from each of the two O atoms) +1 = 20 electrons.
    • The hypochlorite ion, ClO−, contains 13 + 1 = 14 electrons.

  • Ion Channels

    • Ion channels are membrane proteins that allow ions to travel into or out of a cell.
    • Each of these channels are selective as to the type of ion or ions that it allows to pass across the membrane.
    • Most channels are specific (selective) for one ion.
    • Ion pumps are not ion channels but are critical membrane proteins that carry out active transport by using cellular energy (ATP) to "pump" the ions against their concentration gradient.
    • A schematic representation of an ion channel.

  • Characteristics of Mass Spectra

    • The highest-mass ion in a spectrum is normally considered to be the molecular ion, and lower-mass ions are fragments from the molecular ion, assuming the sample is a single pure compound.
    • The molecular ion is the strongest ion in the spectra of CO2 and C3H6, and it is moderately strong in propane.
    • The molecular ion is also the base peak, and the only fragment ions are CO (m/z=28) and O (m/z=16).
    • The molecular ion of propane also has m/z=44, but it is not the most abundant ion in the spectrum.
    • As a rule, odd-electron ions may fragment either to odd or even-electron ions, but even-electron ions fragment only to other even-electron ions.