IT'S TRIVIA TIME:

WHAT NO ONE TELLS YOU ABOUT   OPTICAL ILLUSION 

Optical illusion came from two words which are Optikos a greek word from Medieval Latin means 'visible', 'seen'. And Illusionem a latin word means dishonesty (panlilinlang).

An optical illusion (also called a visual illusion) is an illusion 
caused by the visual system and characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a percept that does not tally with a physical measurement of the stimulus source.

• A Psychologists Johannes Peter Muller invented this theory about optical illusion wherein he wrote 2 books to explain about this in 1826. 

• And 15,000 years ago paleolithic people has already experience optical illusion in the cave.

• According to National Geographic an archeologists Duncan Caldwell studied about different cave's in France and discovered that every cave has one theme on their drawings which are animals that are overlapping each other, just like what he discovered in Font de Gaume cave. 

• The first optical illusion can be seen in coins, 2,500 years ago greek people has a coin that has a 2 heads of a cow that when you stare it has a wolf's face.
• Nowadays, optical illusion can be seen anywhere just like in our house or in buildings, best example of this are putting mirror in a room to get expand.
  
   
• And it has been used on a clothes putting pattern so that the shape of a human can be seen.
  

“SOMETIMES THERE ARE THINGS THAT YOU SHOULDN’T BELIEVE, BE CAREFUL BECAUSE OPTICAL ILLUSION CAN BE PLAYFUL.” :) 

ELECTRON CONFIGURATION

Electronic Configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.

This topic describes each electron as moving independently in an orbital, in an average field created by all other orbitals. Mathematically, configurations are described by Slater determinants or configuration state functions.

Knowledge of the electron configuration of different atoms is useful in understanding the structure of the periodic table of elements. This is also useful for describing the chemical bonds that hold atoms together.

A best example of electron configurations in bulk materials the same idea helps explain the peculiar of lasers and semiconductors.

Semiconductor lasers are lasers based on semiconductor gain media, where optical gain is usually achieved by stimulated emission at an interband transition under conditions of a high carrier density in the conduction band.

  

The physical origin of gain in a semiconductor (for the usual case of an interband transition) is illustrated in Figure 1. Without pumping, most of the electrons are in the valence band. 

 Common materials for semiconductor lasers (and for other optoelectronic devices) are        

• AlGaAs (aluminum gallium arsenide)
• GaP (gallium phosphide)
• InGaP (indium gallium phosphide)
• GaN (gallium nitride)
• InGaAs (indium gallium arsenide)
• GaInNAs (indium gallium arsenide nitride)
• InP (indium phosphide)
• GaInP (gallium indium phosphide)

ULTIMATE GUIDE :
 COLOR PERIODIC TABLES WITH  ELECTRON  CONFIGURATION

This color periodic table contains each element’s number,symbol, name, atomic weight and electron configuration.

Each configuration is written in the noble gas shorthand.This shorthand uses the name of the previous row’s noble gas in brackets torepresent the part of the electron configuration is identical to the noble gas’electron configuration.

 Elements greater than 104 are unknown or unverified. These are denoted with an asterisk on the table and the value listed is a predicted value.

As we go across the rows of the periodic table, the overall shape of the table outlines how the electrons are occupying the shells and subshells.

The first two columns on the left side of the periodic table are where the subshells are being occupied. Because of this, the first two rows of the periodic table are labeled the s block. Similarly, the p block are the right-most six columns of the periodic table, the d block is the middle 10 columns of the periodic table, while the f block is the 14-column section that is normally depicted as detached from the main body of the periodic table.  

The electrons in the highest-numbered shell, plus any electrons in the last unfilled subshell, are called valence electrons; the highest-numbered shell is called the valence shell. (The inner electrons are called core electrons.) The valence electrons largely control the chemistry of an atom. If we look at just the valence shell’s electron configuration, we find that in each column, the valence shell’s electron configuration is the same.

For example, take the elements in the first column of the periodic table: H,Li, Na, K, Rb, and Cs. Their electron configurations (abbreviated for the larger atoms) are as follows, with the valence shell electron configuration highlighted:

H:            1s1

Li:            1s22s1

Na:         [Ne]3s1

K:            [Ar]4s1

Rb:         [Kr]5s1

Cs:          [Xe]6s1

They all have a similar electron configuration in their valence 

shells: a single s electron. Because much of the chemistry of an element is influenced by valence electrons, we would expect that these elements would have similar chemistry—and they do. The organization of electrons in atoms explains not only the shape of the periodic table but also the fact that elements in the same column of the periodic table have similar chemistry.