Star InactiveStar InactiveStar InactiveStar InactiveStar Inactive
 

Regular periodic variations of properties of elements with atomic number (and position in the periodic table).

Latest Articles

  • Gas of rotten eggs

    If you happen to break a rotten egg, then you know the smell of hydrogen sulfide, because the stench of the spoiled egg depends on of its presence in rotting protein substances.

  • Chemistry of the sky

    Chemistry can teach us about the composition of celestial bodies and determine their age.

  • Chemical Safety

    People use chemicals every day for a wide array of purposes, which can include work and house hold duties. Many of us fail to realize that we are actually handling potentially deadly chemicals when we simply clean the bathroom or wash the car. This brings to mind the reason why chemical safety is...

  • The most expensive metal in the world

    Do you think the most expensive metal is gold? No! On earth there are more valuable metals. But we need to divide the value of metals that occur in nature, and metals - isotopes, which are obtained in special laboratories. Let’s look at natural metals first.

  • What's In Your Beverage? How to Ensure Quality Control with CO2 Analytical Support

    Calibration standards, performance audits, and the FDA's never-ending safety, labeling, and inspection requirements are just the tip of the iceberg when it comes to dealing with the increasingly stringent quality control standards of the beverage industry. As these quality standards become...



Most Popular

Effective Nuclear Charge

The nuclear charge experienced by the outermost electrons of an atom, the actual nuclear charge minus the effects of shielding due to inner-shell electrons.
Example: Set of dx2-y2 and dz2 orbitals, those d orbitals within a set with lobes directed along the x-, y-, and z-axes.

Chain Reaction

A reaction that, once initiated, sustains itself and expands. This is a reaction in which reactive species, such as radicals, are produced in more than one step. These reactive species, radicals, propagate the chain reaction.

 

Excited State

Any state other than the ground state of an atom or molecule.

Dry Cells

Ordinary batteries (voltaic cells) for flashlights. radios, and so on, many are Leclanche cells.

Hydration

Reaction of a substance with water.

Sigma Orbital

Molecular orbital resulting from head-on overlap of two atomic orbitals.

Law of Definite Proportions (Law of Constant Composition)

The law stating that a pure substance will always have the same percent by weight. Different samples of a pure compound always contain the same elements in the same proportions by mass.

Aldehyde

Compound in which an alkyl or aryl group and a hydrogen atom are attached to a carbonyl group and a hydrogen atom are attached to a carbonyl group, general formula, O-R-C-H

 

Reaction Stoichiometry

Description of the quantitative relationships among substances as they participate in chemical reactions.

Dextrorotatory

Refers to an optically active substance that rotates the plane of plane polarized light clockwise, also called dextro.