Mole (redirected from Mole (disambiguation))

mole, in chemistry

mole, in chemistry, a quantity of particles of any type equal to Avogadro's number, or 6.02×10²³ particles. One gram-molecular weight of any molecular substance contains exactly one mole of molecules. The term mole is often used in place of gram-molecular weight; e.g., one speaks of 18 grams of water as one mole of water rather than as one gram-molecular weight of water. The mole is a unit in the International System of Units (SI).

---

mole, in zoology

mole, in zoology, common name for the small, burrowing, insectivorous mammals of the family Talpidae, found throughout the temperate Northern Hemisphere. Moles are trapped as pests, although they probably do less damage than the animals they destroy, and for their fur, which is highly valued. Typical moles have rounded bodies about 6 in. (15.2 cm) long covered with soft black or gray fur; they have pointed muzzles and lack external ears. They have acute hearing and a highly developed sense of touch at the ends of their noses and tails; their tiny eyes, covered with skin or buried in fur, are sensitive to changes in light level but provide little visual acuity. Moles have short, powerful legs and extremely broad front feet, which are used as shovels and are equipped with enormous digging claws. They can move backwards almost as rapidly as forwards, and most are good swimmers. Moles tunnel just below the surface of the ground, where they hunt for food. Their tunnels make ridges and mounds in fields, gardens, and lawns; quarters for living, nesting, and wintering are in deeper burrows. A single mole can dig about 20 yd (18 m) of tunnel in a day. Moles are voracious eaters, consuming about half their own weight daily. Their diet consists mainly of earthworms and insects, but also includes small mammals such as mice; one mole may even kill and eat another when they happen to meet. They are solitary most of the year, but during the breeding season they travel in pairs. The litter, born in the spring after four weeks of gestation, consists of two to seven young. Typical species include the common European mole, Talpia europaea, and the eastern, or garden, mole of North America, Scalopus aquaticus, both about 6 in. (15.2 cm) long with a 1-in. (2.54-cm) tail. The largest moles are the western moles of North America, genus Scapanus, which may reach a length of 9 in. (22.9 cm). The smallest New World mole is the 3-in. (7.6-cm) shrew mole, Neurotrichus gibsii, of the Pacific Northwest, which resembles a shrew and prefers a forest habitat, spending much time above ground. The strangest-looking of the family is the star-nosed mole, Condylure christata, of northeastern North America, which has a ring of mobile fleshy protuberances around its snout. This mole is a good diver and leads a semiaquatic life; apparently it uses the protuberances to pick up sounds in the water. There are no true moles in the Southern Hemisphere. The golden moles of S Africa are members of the insectivorous family Chrysochloridae; they are burrowing animals with bright golden fur. There are burrowing rodents in Africa called strand moles and burrowing marsupials in Australia called marsupial moles. True moles are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Insectivora, family Talpidae.

Bibliography

See study by K. Mellanby (1973).

---

mole, in anatomy

mole: see birthmark.

---

mole

 or mol

Standard unit for measuring everyday quantities of such minute entities as atoms or molecules. For any substance, the number of atoms or molecules in a mole is Avogadro's number (6.02 × 10²³) of particles. Defined exactly, it is the amount of pure substance containing the same number of chemical units that there are in exactly 12 g of carbon-12. For each substance, a mole is its atomic weight, molecular weight, or formula weight in grams. The number of moles of a solute in a litre of solution is its molarity (M); the number of moles of solute in 1,000 g of solvent is its molality (m). The two measures differ slightly and have different uses. See also stoichiometry.

---

mole

Any burrowing, often blind insectivore in the family Talpidae (including 42 species of true moles) or Chrysochloridae (18 species of golden moles). Most species have short legs and tail, a pointed head, velvety grayish fur, no external ears, and a strong odour. They range from 3.5 to 8 in. (9 to 20 cm) long. The forelimbs are rotated outward like oars and have broad or pointed claws on the toes. Moles are active day and night, digging surface tunnels in search of earthworms, grubs, and other invertebrates and excavating deep (10 ft [3 m]), vented burrows (molehills) for occupancy. The star-nosed mole (Condylura cristata) of northeastern North America has 22 pink, tentacle-like touch organs radiating from its muzzle.

---

mole

Pigmented flat or fleshy skin mark, made up mostly of cells that produce melanin, which gives moles their light to dark brown or black colour and, in the dermis, a bluish cast. Thicker moles also contain nerve elements and connective tissue. Moles often begin in childhood, usually as flat spots between the dermis and epidermis. Those that remain there are more likely to become malignant. Most move into the dermis and become slightly raised. In children, moles may undergo changes resembling cancer but are benign. Malignant melanoma can begin in moles but almost never before puberty. During pregnancy, moles may enlarge and new ones may appear. Moles sometimes disappear with age. The term nevus refers to a congenital skin mark, whereas a mole may develop after birth. Epidermal nevi are usually the same colour as the surrounding skin.

---

mole

A unit of measurement of molecular weight. Part of the SI system of measurement, one mole (mol) is equal to 6.02257 X 10 to the 23rd molecules. See SI units.

---

mole¹

1. any small burrowing mammal, of the family Talpidae, of Europe, Asia, and North and Central America: order Insectivora (insectivores). They have velvety, typically dark fur and forearms specialized for digging

2. golden mole any small African burrowing molelike mammal of the family Chrysochloridae, having copper-coloured fur: order Insectivora (insectivores)

3. Informal a spy who has infiltrated an organization and, often over a long period, become a trusted member of it

---

mole²

the basic SI unit of amount of substance; the amount that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon-12. The entity must be specified and may be an atom, a molecule, an ion, a radical, an electron, a photon, etc.

---

mole³

1. a breakwater

2. a harbour protected by a breakwater

3. a large tunnel excavator for use in soft rock

---

mole⁴

Pathol a fleshy growth in the uterus formed by the degeneration of fetal tissues

---

mole [mōl]

(chemistry)

An amount of substance of a system which contains as many elementary units as there are atoms of carbon in 0.012 kilogram of the pure nuclide carbon-12; the elementary unit must be specified and may be an atom, molecule, ion, electron, photon, or even a specified group of such units. Symbolized mol.

(civil engineering)

A breakwater or berthing facility, extending from shore to deep water, with a core of stone or earth.

(mechanical engineering)

A mechanical tunnel excavator.

(medicine)

A mass formed in the uterus by the maldevelopment of all or part of the embryo or of the placenta and membranes.

A fleshy, pigmented nevus.

(vertebrate zoology)

Any of 19 species of insectivorous mammals composing the family Talpidae; the body is stout and cylindrical, with a short neck, small or vestigial eyes and ears, a long naked muzzle, and forelimbs adapted for digging.

---

mole

said to lack eyes. [Medieval Animal Symbolism: White, 95–96]

See : Blindness

---

Mole

a quantitative unit of matter characterizing the number of identical structural elements (atoms, molecules, ions, and other particles or their specific groups) in a physical system. A mole is equal to the amount of matter that contains the same number of particles as the number of atoms in an exactly 0.012-kg sample of a nuclide of ¹²C (Avogadro’s number, 6.022 X 10²³). The Russian symbol for mole is mol; the international symbol is mol.

By a decision of the Fourteenth General Conference on Weights and Measures in 1971, the mole was adopted as the seventh fundamental unit in the International System of Units. The multiple unit is the kilomole (1 kmol = 10³ moles).

The mole is used in the derivation of molar quantities such as the molar weight (kg/mol), molar volume (m³ /mol), molar internal energy (J/mol), molar heat capacity (J/[mol.°K]), and molar concentration (mol/m³).

---

Mole

a breakwater that protects the water area of a port from waves and that abuts the shore at one end; a mole may also serve at the same time as a place for hawsers and loading equipment.

In ports located on the open sea, two converging or parallel moles are constructed with gates between them (double, or paired, moles). If the port is situated in a bay whose shore partly protects the water area from wind and waves, the water area is usually bounded by one mole. The design and type of mole is mainly determined by the hydrologic and geologic conditions of the region in which the port is located. Moles may be of the sloping type (built of rubble made of stone or concrete blocks), the vertical type (walls erected with masonry, concrete, or rein-forced-concrete blocks), or a combination of both types. The top part of the mole (the part pushing out into the sea) is made 1-1.5 m higher than the rest and has a signal light or beacon mounted on it.