Colloid

 A colloid, in chemistry, is a mixture in which one substance of microscopically dispersed insoluble particles is suspended throughout another substance.

In  IUPAC definition,  colloid is a short synonym for colloidal system, and colloidal is a state of subdivision such that the molecules or polymolecular particles dispersed in a medium have at least one dimension between approximately 1 nm and 1 μm, or that in a system discontinuities are found at distances of that order.

Types Of Colloid :

Dispersion Phase/ -> Dispersion Medium	Gas	Liquid	Solid
Gas	None	Liquid Aerosol	Solid Aerosol
Liquid	Foam	Emulsion	Sol
Solid	Solid Foam	Gel	Solid-Sol

Colloid Characteristics:

1.Tyndall effect,

Tyndall effect is used commercially to determine the size and density of particles in aerosols and other colloidal matter

source : epicphysics.com

2.Adsorbtion

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface

source : dictionary.com

3. Brownian Motion

Brownian motionis the random motion of particles suspended in a fluid (aliquid or a gas) resulting from their collision with the quick atoms or molecules in the gas or liquid. It makes the colloid cannot gravitate.

source : perpustakaancyber.blogspot.com

4.Coagulation

Coagulation is a process which involves coming together of colloidal particles so as to change into large sized particles which ultimately settle as a precipitate or float on the surface.

source : bisakimia.com

5. Electrophoresis

Electrophoresis is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field

source : majalahkimia.blogspot.com

6. Dialysis

Dialysis is the separation of colloids from dissolved ions or molecules of small dimensions, orcrystalloid, in a solution.

source : catatan.legawa.com

Choir

A choir (/ˈkwaɪ.ər/) (also known as a chorale or chorus) is a musical ensemble of singers. Most choirs are led by a conductor, who leads the performances with arm and face gestures. Most often choirs consist of four sections intended to sing in four part harmony, but there is no limit to the number of possible parts as long as there is a singer available to sing the part.Other than four, the most common number of parts are three, five, six, and eight. Choirs can sing with or without instrumental accompaniment. Singing without accompaniment is called a cappella singing. Accompanying instruments vary widely, from only one instrument (a piano or pipe organ) to a full orchestra of 70-100 musicians; for rehearsals a piano or organ accompaniment is often used, even if a different instrumentation is planned for performance, or if the choir is rehearsing unaccompanied music. Types Of Choir 1.Mixed choirs (with male and female voices). This is perhaps the most common type, usually consisting of soprano, alto, tenor, and bass voices, often abbreviated as SATB. Often one or more voices is divided into two, e.g., SSAATTBB, where each voice is divided into two parts, and SATBSATB, where the choir is divided into two semi-independent four-part choirs. Occasionally baritone voice is also used (e.g., SATBarB), often sung by the higher basses. In smaller choirs with fewer men, SAB, or Soprano, Alto, and Baritone arrangements allow the few men to share the role of both the tenor and bass in a single part. 2.Male choirs, with the same SATB voicing as mixed choirs, but with boys singing the upper part (often called trebles or boy sopranos) and men singing alto (in falsetto), also known as countertenors. This format is typical of the British cathedral choir. 3.Female choirs, usually consisting of soprano and alto voices, two parts in each, often abbreviated as SSAA, or as soprano I, soprano II, and alto, abbreviated SSA. 4.Men's choirs, or Male Chorale, usually consisting of two tenors, baritone, and bass, often abbreviated as TTBB (or ATBB if the upper part sings falsetto in alto range). ATBB may be seen in some barbershop quartet music. 5.Children's choirs, often two-part SA or three-part SSA, sometimes more voices. This includes boy choirs.Boy choirs typically sing SSA or SSAA, sometimes including a tenor part for boys whose voices are changing.