Chemicals and Compounds

What is a chemical?

In its most basic form, a chemical is an element, with a specific molecular composition and may be produced by or used during a natural chemical process. Different kinds of atoms get together to form larger clumps of atoms called molecules. More scientifically, a chemical is a form of matter that has a constant chemical composition and characteristics properties. It can be solid, liquid, gas, or plasma. Diamond, gold, table salt, and refined sugar are some common chemical substances.

Do chemicals change forms?

Chemicals (whether solid, liquid, gas, or plasma) may change between these phases of matter with changes in temperature or pressure. however, they cannot be separated into components by physical separation methods, i.e. without breaking the chemical bonds. Only a chemical reaction can convert one chemical substance into another.

What is an element?

An element is a chemical substance made of specific kinds of atoms that cannot be broken down any further. In short, they are the purest forms of chemicals known to man. Some common elements along with their chemical symbols are:

Iron: Fe, Copper: Cu, Gold: Ag, Silver: Au, Hydrogen: H, etc.

What is a chemical formula?

A chemical formula is a mathematical relationship or rule expressed in symbols. Special kinds of chemical formulas, called molecular formulas, are used to represent the kinds of atoms and the number of each kind of atom in a molecule. The simplest molecules are composed of just two atoms, like oxygen gas (O2), hydrogen gas (H2), and nitrogen gas (N2). Carbon monoxide (CO) is a gas with molecules composed of one atom of carbon and one atom of oxygen, and carbon dioxide (CO2) is a gas with molecules composed of one atom of carbon and two atoms of oxygen.

What is a chemical change?

A chemical change takes place, when the atoms in a molecule are moved around or when atoms are added or taken away. Chemical changes happen on a molecular level when you have two or more molecules that interact and create a new molecule or two. It happens, when the bond between the atoms is created or destroyed. For example, a water molecule (H2O) is made up of two hydrogen atoms and one oxygen atom. If we add a second oxygen atom, we would have hydrogen peroxide (H2O2), which represents a chemical change.

What is a compound?

A compound is a substance made from two or more elements that have bonded chemically with each other. A compound is a completely new material that will often have totally different properties from the elements from which it was made. The elements of a compound can be separated into simpler substances by chemical reactions. Compounds play an integral part in our daily lives; right from the water, we drink to the gasoline that drives our automobile to the medicines that help us fight diseases. Salt is a compound made up of two elements: chlorine, which is poisonous; and sodium, which reacts explosively with water. But, salt does not have any of these properties.

What are the different types of compounds?

There are mainly two types of compounds: molecular and ionic. Molecular compounds are formed when the atoms share the electrons, and ionic compounds are formed when electrons are donated from one atom to another. Molecular compounds form when non-metallic elements react, whereas ionic compounds when non-metals and metals react.

What is an organic compound?

An organic compound is any of a large of chemical compounds, in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen. These include nucleic acids, fats, sugars, proteins, and enzymes. Plastics and petroleum are also organic compounds.

What is an inorganic compound?

An inorganic compound is any substance in which two or more chemical elements, other than carbon are combined, nearly always in definite proportions. Minerals are mainly oxides and sulfides, which are strictly inorganic. Salts and metals are also inorganic compounds. However, there are few organic compounds that don't contain carbon-hydrogen bonds and are thus considered inorganic.

Can chemicals be harmful?

Yes! Certain kinds of chemicals can have negative effects both on people and the environment. The waste from industrial and agricultural processes contains certain chemicals that can lead to catastrophic results. Dioxins are the most toxic man-made organic chemicals known; they cause serious health effects even at levels as low as a few parts per trillion. They are a class of super-toxic chemicals formed as a by-product of the manufacture, molding, or burning of organic chemicals and plastics that contain chlorine. The burning sensation we get from chili peppers is because of a chemical called Capsaicin. Contact with dry ice can result in frostbite and cold burns.

What is the Periodic Table of elements?

The periodic table of elements is a listing of all known elements. It arranges the chemical elements in a pattern so someone can predict the properties of elements based on where they are located on the table. elements are arranged from left to right and from top to bottom on the basis of their atomic numbers, electron configurations, and recurring chemical properties. The first widely recognized periodic table was published in 1869 by Dmitri Mendeleev, a Russian chemist, and inventor.