Pergo FloorMate 100 sq. ft. 4 ft. x 25 ft. x 3 mm. Premium Foam Underlayment for Laminate and Floating Wood Floors

100 or one hundred (Roman numeral: C) is the natural number following 99 and preceding 101.

Twenty-Five or 25 may refer to:

• 25 (number)
• one of the years 25 BC, AD 25, 1925, 2025

3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious and cultural significance in many societies.

4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5.

4 is the smallest square number > 1, the smallest semiprime and composite number, and the 3rd highly composite number.

The number 4 is considered unlucky in many East Asian cultures.

Floating may refer to:

• a type of dental work performed on horse teeth
• use of an isolation tank
• the guitar-playing technique where chords are sustained rather than scratched
• Floating (play), by Hugh Hughes
• Floating (psychological phenomenon), slipping into altered states
• Floating exchange rate, a market-valued currency
• Floating voltage, and floating ground, a voltage or ground in an electric circuit that is not connected to the Earth or another reference voltage
• Floating point, a representation in computing of rational numbers most commonly associated with the IEEE 754 standard
• Floating (film), a 1997 American drama film

Foams are two-phase material systems where a gas is dispersed in a second, non-gaseous material, specifically, in which gas cells are enclosed by a distinct liquid or solid material.^{: 6 : 4} The foam "may contain more or less liquid [or solid] according to circumstances",^: 6 although in the case of gas-liquid foams, the gas occupies most of the volume.^: 4 The word derives from the medieval German and otherwise obsolete veim, in reference to the "frothy head forming in the glass once the beer has been freshly poured" (cf. ausgefeimt).^: 1

Theories regarding foam formation, structure, and properties—in physics and physical chemistry—differ somewhat between liquid and solid foams in that the former are dynamic (e.g., in their being "continuously deformed"), as a result of gas diffusing between cells, liquid draining from the foam into a bulk liquid, etc.^: 1–2 Theories regarding liquid foams have as direct analogs theories regarding emulsions,^: 3 two-phase material systems in which one liquid is enclosed by another.

In most foams, the volume of gas is large, with thin films of liquid or solid separating the regions of gas. A bath sponge and the head on a glass of beer are examples of foams; soap foams are also known as suds.

Solid foams can be closed-cell or open-cell. In closed-cell foam, the gas forms discrete pockets, each completely surrounded by the solid material. In open-cell foam, gas pockets connect to each other. A bath sponge is an example of an open-cell foam: water easily flows through the entire structure, displacing the air. A sleeping mat is an example of a product composed of closed-cell foam.

Foams are examples of dispersed media. In general, gas is present, so it divides into gas bubbles of different sizes (i.e., the material is polydisperse)—separated by liquid regions that may form films, thinner and thinner when the liquid phase drains out of the system films. When the principal scale is small, i.e., for a very fine foam, this dispersed medium can be considered a type of colloid.

Foam can also refer to something that is analogous to foam, such as quantum foam.

Underlayment may refer to:

• Underlay, a material placed underneath floor carpet, other flooring materials, or mattress bedding
• Underlayment, a water-resistant or waterproof layer used beneath many types of commercially available roofing material
  • Bituminous waterproofing, systems designed to protect residential and commercial buildings
  • SDM strength film, a kind of High Density Polyethylene (HDPE) Cross Laminated Strength Film
  • Tar paper, a heavy-duty paper used in construction
• Underlayment in road construction such as nonwoven fabric
• Underlay, a material in sewing
• Underlay, a technique in some types of surgery such as myringoplasty
• Underlay, a material in printing

Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree, it performs a mechanical-support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients among the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fibers.

Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.

As of 2020, the growing stock of forests worldwide was about 557 billion cubic meters. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 2008, approximately 3.97 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.

Wood is scientifically studied and researched through the discipline of wood science, which was initiated since the beginning of the 20th century.

X, or x, is the twenty-fourth letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ex (pronounced ), plural exes.