nucleus
nucleus — noun
1. The tiny, positively charged core that sits at the centre of every atom, contain
The tiny, positively charged core that sits at the centre of every atom, containing closely packed protons and uncharged neutrons that together make up the bulk of the atom's weight.
Tamar's physics project explained how protons and neutrons are packed inside an atom's nucleus.
collocation: packed inside the nucleus
Splitting the nucleus of a uranium atom releases a huge amount of energy.
grammar pattern: split the nucleus of + noun
The nucleus of a hydrogen atom contains just one proton and no neutrons.
Antonia drew a diagram showing electrons moving around the nucleus of a lithium atom.
Almost all atomic mass sits in the nucleus, not in the orbiting electrons.
- core
Less precise; 'core' can refer to the center of any object, while 'nucleus' is specific to atoms in physics.
- electron cloud
The region around the nucleus where electrons are found.
文法句型
the nucleus of + noun
用法筆記
Plural form 'nuclei' (pronounced /ˈnjuːkliaɪ/) is common in scientific writing. The adjective 'nuclear' is used in terms such as 'nuclear physics' and 'nuclear energy'.
常見錯誤
2. The membrane-bound organelle inside eukaryotic cells that holds the genetic mate
The membrane-bound organelle inside eukaryotic cells that holds the genetic material and directs the cell's growth, reproduction, and basic functions.
Under the microscope, Jin could clearly see the round shape of the onion cell's nucleus.
possessive: cell's nucleus
The nucleus of a human cell holds twenty-three pairs of chromosomes made of DNA.
grammar pattern: the nucleus of + noun (biology)
Before a cell divides, its nucleus first copies all the genetic material inside it.
Ayana's biology teacher explained that the nucleus acts as the command centre of the cell.
Damage to the nucleus can prevent a cell from repairing itself or dividing properly.
- cell nucleus
Full term used when the context of 'nucleus' alone might be ambiguous between atom and cell.
- cytoplasm
The material outside the nucleus but inside the cell membrane.
文法句型
the nucleus of + noun
用法筆記
In biology, the plural 'nuclei' (/ˈnjuːkliaɪ/) is standard. Eukaryotic cells have a true nucleus enclosed by a membrane; prokaryotic cells such as bacteria do not.
常見錯誤
3. The most important people or elements within a larger organisation or system, ar
The most important people or elements within a larger organisation or system, around which all other parts gather or develop.
A small nucleus of parents kept the school sports programme running for over a decade.
collocation: a small nucleus of + people
The old market square became the nucleus around which the modern city centre grew.
grammar pattern: the nucleus around which
Hamza's team formed the creative nucleus of the advertising agency, generating the most original ideas.
These three principles form the nucleus of the company's environmental policy.
The club began with a nucleus of five members and grew to over two hundred.
- core
Nearly interchangeable; 'core' is slightly more common in everyday language, while 'nucleus' has a more formal or organized feel.
- heart
More emotional and less structured; 'the heart of the community' emphasises warmth, while 'nucleus' suggests a functional centre.
- hub
Emphasises activity and connection (e.g. a transport hub); 'nucleus' focuses more on essential membership.
文法句型
a nucleus of + noun (group/people/things)
the nucleus of + noun
用法筆記
Typically followed by 'of' to specify the larger entity. Common in business, politics, and community contexts. Unlike the scientific senses, this figurative sense describes an abstract or social centre rather than a physical one.
常見錯誤
4. The solid, icy central body of a comet, made up of frozen gases, dust, and rock,
The solid, icy central body of a comet, made up of frozen gases, dust, and rock, which heats up and releases gas and dust when it approaches the Sun.
The spacecraft sent back clear images of the comet's dark, potato-shaped nucleus.
possessive: comet's nucleus
Near the Sun, the comet's nucleus released gas and dust, forming a glowing coma.
collocation: nucleus releases gas and dust
Scientists estimate that the nucleus of this comet is roughly five kilometres across.
Tariro studied data suggesting the comet's nucleus contains frozen carbon dioxide mixed with water ice.
文法句型
the nucleus of a comet
用法筆記
A specialised astronomy term. The plural 'nuclei' is used when referring to multiple comets. The nucleus is distinct from the coma (the cloud of gas around it) and the tail.