What are the 7 properties of atoms?
Answer:
Following is a series of terms and concepts that relate to the Properties of Atoms as determined by Electronic Configurations.
Anion ,Atomic Radius, Cation , Electron Affinity, Electonegativity, Ionization Potential , Nobel Gas Configuration Oxidation Number , Pauling Scale , Periodic Chart Trends,
Radius , Stability Factors
Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions.
1. Atomic Number
Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral, the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties of the atom. The lightest atom, hydrogen, has an atomic number equal to one, contains one proton, and (if electrically neutral) one electron. The most massive stable atom found in nature is bismuth (Z = 83). More massive unstable atoms also exist in nature, but they break apart and change into other atoms over time. Scientists have produced even more massive unstable elements in laboratories.
2. Mass Number
The total number of protons and neutrons in the nucleus of an atom is the mass number of the atom (abbreviated A). The mass number of an atom is an approximation of the mass of the atom. The electrons contribute very little mass to the atom, so they are not included in the mass number. A stable helium atom can have a mass number equal to three (two protons plus one neutron) or equal to four (two protons plus two neutrons). Bismuth, with 83 protons, requires 126 neutrons for stability, so its mass number is 209 (83 protons plus 126 neutrons).
3. Atomic Mass and Weight
Scientists usually measure the mass of an atom in terms of a unit called the atomic mass unit (abbreviated amu). They define an amu as exactly 1/12 the mass of an atom of carbon with six protons and six neutrons. On this scale, the mass of a proton is 1.00728 amu and the mass of a neutron is 1.00866 amu. The mass of an atom measured in amu is nearly equal to its mass number.
4.Atomic Radius The Atomic Radius is a very common method of measuring the relative sizes of atoms. It is determined as half the distance between two identical atoms when bonded together. For instance, half the distance between two atoms of Oxygen in O2 will be the atomic radius of an Oxygen atom
5.Electron Affinity :Electron Affinity is a measure of the desire or ability of an atom to gain electrons. It is an energy concept. The formal definition states that Electron Affinity is the amount of energy released when an electron as added to an atom. Most atoms tend to lose energy when they gain electrons. Some atoms do not. Those that do not tend to appear in the lower left corner of the Periodic Chart. The concept of Electron Affinity tends to be viewed as an exothermic process. The elements located in the upper right corner of the Periodic Chart have the high E.A. values while those in the lower left corner have the low E.A. values. This is interpreted as meaning that elements in the upper right corner are usually found an anions while those in the lower left corner are usually not found as anions. A generic equation of the E.A. process would be as follows.
6.Electronegativity:The concept of Electronegativity refers to the ability of a bonded atom to pull electrons towards itself.
It is defined as the relative ability of an atom in a molecule to attract electrons towards itself. As atoms bond, electrons are shared or transferred. The decision about sharing or transferring electrons is made based upon the electronegativities of the two bonded atoms.
The atom with the higher electronegativity will dominate the electrons.
The greater the difference between the electronegativity values of the two bonded atoms, the more the electrons will be transferred and the less they will be shared.
In order to be able to determine electronegativity values it is important to observe the behavior of atoms in a bonded situation. Consequently, the Noble Gases do not usually appear with listed electronegativity values.
7. Ionization Energy ( or Potential) Ionization Potential is an energy term. It refers to the process of cation formation. The definition states that Ionization Potential is the amount of energy required to remove the highest energy electron from the valence level of an atom. Because energy must be put into the system, the process in endothermic. Consequently, from an energy point of view, this is an unfavorable process. Atoms in the upper right hand corner of the Periodic Chart have the largest I.P. values and the elements in the lower left corner of the Periodic Chart have the lowest I.P. values. Because the elements in the lower left corner need the smaller amounts of energy to form cations, these elements are usually found as cations in chemical process. The elements in the upper right corner, on the other hand, need larger amounts of energy to form cations. Therefore, they are not usually going to appear as cations.
There are additional Ionization Potential terms, such as 2nd I.P., 3rd I.P., and so on. This refers to the sequential removal of electrons from an atom. There will be one I.P. value for each electron that at system has.
Periodic Chart Trends The Periodic Chart Trends refer to overall pattern of changes in Properties of Atoms that take place within Groups and Periods on the Periodic Chart. Frequently, it is more useful to know how different elements compare than it is to know specific numerical information. Therefore, the Trends have been developed to aid in doing comparative work. While there will be exceptions, or deviations, in the Trends, the patterns are generally reliable.
8. Stability Factors :The Stability Factors referred to here are used to determine the numbers of electrons that are gained or lost in chemical bonding processes. As atoms struggle to improve stability by bonding, there are certain methods available to them. Generally, there are four factors that appear most frequently. Listed here, in order of decreasing importance:
9.Desire to achieve a configuration that is isoelectronic with a Noble Gas.
Desire to lose all valence level electrons.
Desire to lose the valence level p orbital electrons.
Desire to maintain filled, empty, and half-filled sets of orbitals.
The desires to lose valence level electrons or valence level p orbital electrons are very similar in terms of preference. In some atoms one of the factors is more important, and for other elements the other factor is more important. Regardless, the idea of half-filling a set of orbitals will provide some stability, but it is definitely a very low priority.
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