States of Matter

Matter is anything that has mass.

Gases, liquids and solids are all made up of microscopic particles, but the behaviors of these particles differ in the three phases. The following figure illustrates the microscopic differences.

Microscopic view of a gas. Microscopic view of a liquid. Microscopic view of a solid.

Some Characteristics of Gases, Liquids and Solids and the Microscopic Explanation for the Behaviour

gas liquid solid

assumes the shape and volume of its container

particles can move past one another

assumes the shape of the part of the container which it

occupies particles can move/slide past

one another

retains a fixed volume and shape

rigid - particles locked into place

compressible lots of free space between

particles

not easily compressible little free space between

particles

not easily compressible little free space between

particles

flows easily particles can move past one

another

flows easily particles can move/slide past

one another

does not flow easily rigid - particles cannot

move/slide past one another

DIAGRAM OF MATTER

Pure substances are defined as substances that are made of only one type of atom or molecule, and the purity of a substance is the measure of the extent to which a given substance is pure. The physical properties of a pure substance include well-defined melting and boiling points.

An element is a pure substance which cannot be broken down by further chemical techniques. These include heating, cooling, electrolysis and reacting with other chemicals. (By the way, it is correct that an atom can be destroyed, but NOT by chemical means. You must use a more powerful reaction, called a nuclear reaction, to destroy or change atoms. That is a topic for a lesson in a different unit.)

A compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two. The key distinction is that compounds break down whereas the SAME techniques do not cause an element to break down.

An acid is a chemical substance whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals to form salts.

In chemistry, a base is a substance that, in aqueous solution, is slippery to the touch, tastes bitter, changes the color of indicators, reacts with acids to form salts, and promotes certain chemical reactions.

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of related numbers of cations and anions so that the product is electrically neutral.

In chemistry, a nonmetal or non-metal is a chemical element which mostly lacks metallic attributes. Physically, nonmetals tend to be highly volatile (easily vaporised), have low elasticity, and are good insulators of heat and electricity; chemically, they tend to have high ionisation energy and electronegativity values and gain or share electrons when they react with other elements or compounds. Seventeen elements are generally classified as nonmetals; most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine); and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).

In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds.

A metalloid is a chemical element that has properties in between those of metals and nonmetals. There is no standard definition of a metalloid, nor is there complete agreement as to which elements are appropriately classified as such. Despite this lack of specificity, the term remains in use in chemistry literature.

In chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.

In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solvent does the dissolving. The solution more or less takes on the characteristics of the solvent including its phase, and the solvent is commonly the major fraction of the mixture.

In chemistry, a suspension is a heterogeneous mixture containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than 1 micrometer.[1] The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. Unlike colloids, suspensions will eventually settle. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the suspended particles are smaller and do not settle.[2] Colloids and suspensions are different from solutions, in which the dissolved substance (solute) does not exist as a solid, and solvent and solute are homogeneously mixed.

Colloids - particles intermediate in size between those found in solutions and suspensions can be mixed such that they remain evenly distributed without settling out. These particles range in size from 10-8 to 10-

6 m in size and are termed colloidal particles or colloids. The mixture they form is called a colloidal dispersion. A colloidal dispersion consists of colloids in a dispersing medium.

A homogeneous mixture is simply any mixture that is uniform in composition throughout.

A heterogeneous mixture is made of different substances that remain physically separate. Heterogeneous mixtures always have more than one phase (regions with uniform composition and properties).

Physical properties of matter are categorized as either Intensive or Extensive:

Intensive - Properties that do not depend on the amount of the matter present.

Color Odor Luster - How shiny a substance is. Malleability - The ability of a substance to be beaten into thin sheets. Ductility - The ability of a substance to be drawn into thin wires. Conductivity - The ability of a substance to allow the flow of energy or electricity. Hardness - How easily a substance can be scratched. Melting/Freezing Point - The temperature at which the solid and liquid phases of a

substance are in equilibrium at atmospheric pressure. Boiling Point - The temperature at which the vapor pressure of a liquid is equal to

the pressure on the liquid (generally atmospheric pressure). Density - The mass of a substance divided by its volume

Extensive - Properties that do depend on the amount of matter present.

Mass - A measurement of the amount of matter in a object (grams). Weight - A measurement of the gravitational force of attraction of the earth acting

on an object. Volume - A measurement of the amount of space a substance occupies. Length