Each electron in an atom is described by four different quantum numbers. The first three (n, l, ml) specify the particular orbital of interest, and the fourth (ms) specifies how many electrons can occupy that orbital.able of Allowed Quantum Numbers. n l ml Number of orbitals Orbital Name Number of electrons 1 0 0 1 1s 2 2 0 0 1 2s 2 1 -1, 0, +1 3 2p 6 3 0 0 1 3s 2 1 -1, 0, +1 3 3p 6 2 -2, -1, 0, +1, +2 5 3d 10 4 0 0 1 4s 2 1 -1, 0, +1 3 4p 6 2 -2, -1, 0, +1, +2 5 4d 10 3 -3, -2, -1, 0, +1, +2, +3 7 4f 14.
Rat droppings are a key sign of a rat infestation; the mess and debris they leave in their wake is unmistakable. In addition to scattered nesting materials; debris from chewing, feeding and gnawing; rodents excrete urine and feces every few steps they take along their habitual paths of travel.
The brown rat is a rather large true murid and can weigh twice as much as a black rat and many times more than a house mouse. The length is commonly in the range of 20 to 25 cm (8 to 10 in), with the tail a further 18 to 25 cm (7 to 10 in), thus being roughly the same length as the body.he brown rat, also referred to as common rat, street rat, sewer rat, Hanover rat, Norway rat, brown Norway rat, Norwegian rat, or wharf rat (Rattus norvegicus) is one of the best known and most common rats.