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the number of unpaired electron orbital

Posted by Sunzz SArah On 5:49 AM 0 comments

To determine the number of orbitals that have unpaired electrons in transition elements based on the number of gas atoms begin. Practical formula:

1. Atomic number VIIA + (1-7)

Unpaired electron orbital = 1 / 2 VIIIA + 1

2. Atomic number VIIIA + 8

Unpaired electron orbital = 1 / 2 VIIIA + 2

3. Atomic number VIIIA + 9

Unpaired electron orbital = 1 / 2 VIIIA + 3

And so on until VIIIA + 12 = 1 / 2 VIIIA + 6

PERIODIC PROPERTIES

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A. Atomic radius

The distance between the center core and outer shell.

Positive charge that is felt by electrons called the effective nuclear charge. The larger the effective nuclear charge, the more attracted by the nucleus. Basically cations have smaller radii while the anion has a larger radius.

B. Ionization potential - ionization energy

Ionization energy is the energy required to release one electron in the outer shell (valence electrons) of atoms or elements in a gaseous state. Ionization energy will be even greater if the effective nuclear charge larger or smaller atomic size.

C. electron affinity

Electron affinity is the energy released when an atom or ion in a gaseous state capture electrons from the outside. Generally negative electron affinity (energy released), but in some atoms have an electron affinity is positive. The smaller the size of atoms, electrons are captured will be closer to the nucleus, the energy liberated as a result will be even greater.

D. electronegativity

Electronegativity is the tendency of an atom to attract electrons (the tendency to be negative ions).

E. basicity

Power of an atom to be acidic or alkaline.

F. reactivity

Reactivity of an element associated with later elements of the release or capture of electrons. Elements of class IA and VIIA is the most reactive element. In group IA, the more downward the more reactive but otherwise in group VIIA is getting to the bottom of the less reactive.

HISTORY OF PERIODIC SYSTEM

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A. Rules triads (Deboreiner)

Three elements with similar chemical properties are grouped together, which is the mass number (NM) elements in the middle is the average of the other two elements

B. Law of octaves (Newlands)

If the elements arranged according to rising numbers of mass number (NM), then the nature of the chemical elements will be repeated on the 8th

C. The long form of periodic system (Mendeleyev)

Periodic system is based on the increase of BA

D. Modern periodic system (Moseley)

Periodic system is based on the atomic number increases (NA).

PERIODIC SYSTEM OF ELEMENTS COMPILATION

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- Long-form periodic system based on atomic number (increase in the number of protons or nuclear charge)

- Long-form periodic system is divided into: Period and Group.

ELECTRON CONFIGURATION

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Electron configuration is the arrangement of electrons in the skin and sub-skin within the atoms of an element. Rules laying electrons follow the following rules:

a. AUF principle BAU

Electrons in an atom are filled starting from the lowest energy level first.

b. Hund's rule

Unpaired electrons are not allowed prior to each occupied by one electron orbits.

c. prohibition Pauli

The electrons of an atom may not have the same four quantum numbers.

d. Orbital full and half full.

quantum number

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Quantum numbers consist of:

1. Principal quantum number (n)

Shows the occupied electron shells

2. Azimuthal quantum number (l)

Shows the occupied electron sub-skin

3. Magnetic quantum number (m)

Shows the orbital in the subshell

4. Spin quantum number (s)

Indicate the direction of electron spin.

ATOM THEORY

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1. Leucippos and Demokrius

Atom is the smallest part of a substance that can not be divided.

2. John Dalton

Atom is:

- The smallest particles contained in a substance

- Can not be described and can not be converted into other atoms

- Different element atoms with atoms of other elements

- Atoms of certain elements have the same properties

- During the reaction, the atom has not changed but its composition is different.

3. J. J. Thomson

Atom is:

- Is a solid ball, where protons and electrons scattered inside

- A positive charge = negative charge

4. Rutherford

Atom is:

- Based on the alpha ray scattering experiment

- Consists of atomic nuclei which is the center of mass and positively charged, while the negatively charged electrons spinning around the nucleus of the atom.

weaknesses:

- Based on Maxwell's theory, the atom is unstable

- A continuous spectrum when the spectrum of atomic lines.

5. Niels Bohr

Atom is:

- The basis of Rutherford's atomic theory and quantum theory

- Consists of atomic nuclei which is the center of mass and positive charge, while the negatively charged electrons spinning around the nucleus of the atom at a particular energy level (specific trajectory).

Remember:

- Electrons moving around atoms on certain trajectories without removing energy

- Electrons can move from track to track low-level high energy level by absorbing energy and vice versa.

6. Wave mechanics (Louis De Broglie)

Atom is:

- Basic atomic theory, Bohr Rutheford

- Consists of atomic nuclei which is the center of mass and positive charge, while the negatively charged electrons spinning around the nucleus in orbitals