P n.
the sixteenth letter of the English alphabet, is a nonvocal consonant whose form and value come from the Latin, into which language the letter was brought, through the ancient Greek, from the Phonician, its probable origin being Egyptian. Etymologically P is most closely related to b, f, and v; as hobble, hopple; fathe…
Q n.
, the seventeenth letter of the English alphabet, has but one sound (that of k), and is always followed by u, the two letters together being sounded like kw, except in some words in which the u is silent. See Guide to Pronunciation, § 249. Q is not found in Anglo-Saxon, cw being used instead of qu; as in cwic, quick; c…
R n.
R, the eighteenth letter of the English alphabet, is a vocal consonant. It is sometimes called a semivowel, and a liquid. See Guide to Pronunciation, §§ 178, 179, and 250-254. "R is the dog's letter and hurreth in the sound." B. Jonson.
RADIUM n.
temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, and gamma rays (see these terms). By reason of these rays they ionize gases, affect photographic plates, cause sores on the skin, and produce many other striking effects. Their degree of activity depends on…
S n.
the nineteenth letter of the English alphabet, is a consonanat, and is often called a sibilant, in allusion to its hissing sound. It has two principal sounds; one a more hissing, as in sack, this; the other a vocal hissing (the same as that of z), as in is, wise. Besides these it sometimes has the sounds of sh and zh,…