n

• 英语字母表的第十四个字母，为辅音。表示浊齿龈鼻音 /n/，发音时舌抵齿龈，气流从鼻腔流出。也用作北、数学中不定数、化学中氮元素和物理学中牛顿的符号。

The fourteenth letter of the English alphabet and the eleventh consonant, representing the voiced alveolar nasal sound /n/. As a grapheme, 'N' is produced by pressing the tongue against the alveolar ridge and allowing air to pass through the nose. It is one of the most frequent letters in English, appearing in a wide range of common words. It functions as an abbreviation for north, an indefinite number in mathematics, a designation for nitrogen in chemistry, a symbol for newton in physics, and the fourteenth item in a sequence.

1. The fourteenth letter of the English alphabetA1formal

   The uppercase or lowercase character (N, n) that constitutes the fourteenth symbol in the Latin-based English alphabet, classified as a consonant. It represents a voiced alveolar nasal sound produced by the tongue tip making contact with the alveolar ridge while air exits through the nose. It is the most frequently occurring consonant in many languages and can be syllabic in words like 'button'.

   英文字母第十四个字母

   • The word 'night' begins with the letter N.
   • The N in 'autumn' is silent.
   • She wrote the lowercase n with a single hump.
   • In the NATO alphabet, N is 'November'.
   • The consonant cluster 'ng' is represented by a separate phoneme from N.

2. An abbreviation for northA1formal

   The uppercase letter N used as the standard abbreviation for the cardinal direction north. It is commonly found on compass roses, maps, weather reports, and in the naming of regions like North America or the North Pole. It is a fundamental marker for navigation and orientation.

   北（方向）

   • The compass needle points to N.
   • They traveled N for two days to reach the mountains.
   • The cold front is moving in from the N.
   • The map legend shows N at the top.
   • North Carolina is a state in the southeastern US.

3. An indefinite number in mathematicsB1formalscientific

   The lowercase or uppercase letter n used as a variable to represent an unspecified or arbitrary natural number or integer in mathematics. It commonly appears in sequences (the nth term), summations, and limits, functioning as a placeholder for any whole number.

   数学中的不定数

   • Find the value of the nth term in the sequence.
   • The formula is true for all positive integers n.
   • We calculated the sum from i=1 to n.
   • The limit of the function as n approaches infinity is zero.
   • For any given n, the algorithm completes in n squared steps.

4. The chemical symbol for nitrogenB1formalscientific

   The one-letter chemical symbol representing the element nitrogen, atomic number 7. It is a colorless, odorless diatomic gas (N₂) that makes up about 78% of Earth's atmosphere. It is an essential nutrient for plants, a key component of amino acids and nucleic acids, and is widely used in fertilizers and industrial processes.

   氮（化学元素）

   • Nitrogen, symbolized by N, is the most abundant gas in our atmosphere.
   • The chemical formula for ammonia is NH₃, containing one N atom.
   • Liquid N is used to freeze biological samples.
   • A lack of N in soil can cause plants to turn yellow.
   • The N cycle is crucial for understanding ecosystems.

5. The symbol for newton, the unit of forceB2formalscientific

   The uppercase letter N used as the international standard symbol for the newton, the SI derived unit of force. One newton is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. It is named after Sir Isaac Newton in recognition of his foundational work in classical mechanics.

   牛顿，力的单位

   • The box was pushed with a force of 50 N.
   • One N is approximately equal to 0.225 pounds of force.
   • The structural beam can withstand a load of up to 5000 N.
   • Newton's second law states F = m * a, where F is measured in N.
   • The tension in the rope was measured at 120 N.