A report on Chemistry and Chemical substance

An oil painting of a chemist (Ana Kansky, painted by Henrika Šantel in 1932)

Steam and liquid water are two different forms of the same chemical (pure) substance: water.

Laboratory, Institute of Biochemistry, University of Cologne in Germany.

Colors of a single chemical (Nile red) in different solvents, under visible and UV light, showing how the chemical interacts dynamically with its solvent environment.

Solutions of substances in reagent bottles, including ammonium hydroxide and nitric acid, illuminated in different colors

Native sulfur crystals. Sulfur occurs naturally as elemental sulfur, in sulfide and sulfate minerals and in hydrogen sulfide.

A diagram of an atom based on the Bohr model

Potassium ferricyanide is a compound of potassium, iron, carbon and nitrogen; although it contains cyanide anions, it does not release them and is nontoxic.

Standard form of the periodic table of chemical elements. The colors represent different categories of elements

Cranberry glass, while appearing homogeneous, is a mixture consisting of glass and gold colloidal particles of about 40nm in diameter, giving it a red color.

Carbon dioxide (CO2), an example of a chemical compound

Chemicals in graduated cylinders and beaker.

A ball-and-stick representation of the caffeine molecule (C8H10N4O2).

A 2-D structural formula of a benzene molecule (C6H6)

Diagram showing relationships among the phases and the terms used to describe phase changes.

An animation of the process of ionic bonding between sodium (Na) and chlorine (Cl) to form sodium chloride, or common table salt. Ionic bonding involves one atom taking valence electrons from another (as opposed to sharing, which occurs in covalent bonding)

In the methane molecule (CH4), the carbon atom shares a pair of valence electrons with each of the four hydrogen atoms. Thus, the octet rule is satisfied for C-atom (it has eight electrons in its valence shell) and the duet rule is satisfied for the H-atoms (they have two electrons in their valence shells).

During chemical reactions, bonds between atoms break and form, resulting in different substances with different properties. In a blast furnace, iron oxide, a compound, reacts with carbon monoxide to form iron, one of the chemical elements, and carbon dioxide.

The crystal lattice structure of potassium chloride (KCl), a salt which is formed due to the attraction of K+ cations and Cl− anions. Note how the overall charge of the ionic compound is zero.

Hydrogen bromide exists in the gas phase as a diatomic molecule

Democritus' atomist philosophy was later adopted by Epicurus (341–270 BCE).

15th-century artistic impression of Jābir ibn Hayyān (Geber), a Perso-Arab alchemist and pioneer in organic chemistry.

Antoine-Laurent de Lavoisier is considered the "Father of Modern Chemistry".

In his periodic table, Dmitri Mendeleev predicted the existence of 7 new elements, and placed all 60 elements known at the time in their correct places.

Top: Expected results: alpha particles passing through the plum pudding model of the atom undisturbed.
Bottom: Observed results: a small portion of the particles were deflected, indicating a small, concentrated charge.

It is a natural science that covers the elements that make up matter to the compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.

- Chemistry

Later with the advancement of methods for chemical synthesis particularly in the realm of organic chemistry; the discovery of many more chemical elements and new techniques in the realm of analytical chemistry used for isolation and purification of elements and compounds from chemicals that led to the establishment of modern chemistry, the concept was defined as is found in most chemistry textbooks.

- Chemical substance

3 related topics with Alpha

Chemical compound

1 links

A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds.

Many chemical compounds have a unique CAS number identifier assigned by the Chemical Abstracts Service.

A thermite reaction using iron(III) oxide. The sparks flying outwards are globules of molten iron trailing smoke in their wake.

Chemical reaction

1 links

Antoine Lavoisier developed the theory of combustion as a chemical reaction with oxygen.

As seen from the equation CH4 + 2O2 -> CO2 + 2 H2O, a coefficient of 2 must be placed before the oxygen gas on the reactants side and before the water on the products side in order for, as per the law of conservation of mass, the quantity of each element does not change during the reaction

An example of organic reaction: oxidation of ketones to esters with a peroxycarboxylic acid

Isomerization of azobenzene, induced by light (hν) or heat (Δ)

Representation of four basic chemical reactions types: synthesis, decomposition, single replacement and double replacement.

Sodium chloride is formed through the redox reaction of sodium metal and chlorine gas

Ferrocene – an iron atom sandwiched between two C5H5 ligands

In this Paterno–Büchi reaction, a photoexcited carbonyl group is added to an unexcited olefin, yielding an oxetane.

Schematic potential energy diagram showing the effect of a catalyst in an endothermic chemical reaction. The presence of a catalyst opens a different reaction pathway (in red) with a lower activation energy. The final result and the overall thermodynamics are the same.

Solid heterogeneous catalysts are plated on meshes in ceramic catalytic converters in order to maximize their surface area. This exhaust converter is from a Peugeot 106 S2 1100

Mechanism of electrophilic aromatic substitution

Electrophilic addition of hydrogen bromide

Acid-catalyzed addition-elimination mechanism

The Cope rearrangement of 3-methyl-1,5-hexadiene

Illustration of the induced fit model of enzyme activity

Thermite reaction proceeding in railway welding. Shortly after this, the liquid iron flows into the mould around the rail gap.

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another.

Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.

Mixture

0 links

In chemistry, a mixture is a material made up of two or more different chemical substances which are not chemically bonded.

Chemical substance