| californium |
a synthetic radioactive chemical element having ninety-eight protons in each nucleus. (symbol: Cf) |
| carbon |
a chemical element that has six protons in each nucleus and that occurs in pure forms as diamond and graphite, or in a large variety of compounds such as carbon dioxide, carbohydrates, and petroleum hydrocarbons. (symbol: C) [1/7 definitions] |
| cell |
a microscopic unit of plant or animal life, usually containing a nucleus and surrounded by a very thin membrane. [1/4 definitions] |
| centrosome |
a minute protoplasmic body, near the nucleus in most animal cells, that divides in mitosis. |
| cerium |
a highly reactive chemical element of the rare-earth group that has fifty-eight protons in each nucleus and that occurs naturally only in compounds. (symbol: Ce) |
| cesium |
a highly reactive chemical element of the alkali metal group that has fifty-five protons in each nucleus and that occurs in pure form as a soft, silvery metal melting to a heavy liquid just above room temperature. (symbol: Cs) [1/2 definitions] |
| chlorine |
a chemical element of the halogen group that has seventeen protons in each nucleus, occurs naturally only in compounds such as sodium chloride and chloroform, and can be isolated in pure form as a toxic yellow-green gas. (symbol: Cl) [1/2 definitions] |
| chromium |
a chemical element that has twenty-four protons in each nucleus and that occurs as a silver-gray, lustrous, corrosion-resistant solid metal, chiefly used in electroplating, alloys such as stainless steel, or compounds with other elements. (symbol: Cr) |
| cobalt |
a chemical element that has twenty-seven protons in each nucleus and occurs as a brittle silver-white solid metal, used in a variety of alloys to increase hardness. (symbol: Co) |
| coma2 |
the cloud around a comet's nucleus; the head of a comet. [1/3 definitions] |
| comet |
a heavenly body orbiting the sun and having a nucleus surrounded by a nebulous sheath that may form an elongated tail when the body comes close to the sun. |
| copper |
a chemical element that has twenty-nine protons in each nucleus and occurs as a reddish brown, corrosion-resistant solid metal with excellent electrical conductivity, widely used for wiring and in pipes, and in alloys such as brass and bronze. (symbol: Cu). [1/7 definitions] |
| curium |
a synthetic radioactive chemical element that has ninety-six protons in each nucleus. (symbol: Cm) |
| cytoplasm |
the ground protoplasm of cells that is outside the nucleus. [2 definitions] |
| deuterium |
an isotope of hydrogen that has one proton and one neutron in each nucleus; heavy hydrogen. (Cf. protium, tritium.) |
| deuteron |
a particle composed of one proton and one neutron that is equivalent to the nucleus of a deuterium atom and that has a positive charge. |
| diploid |
in biology, a cell or nucleus containing two of each non-sex-determining chromosome. [1/3 definitions] |
| disintegrate |
to decay or be transformed, as an atomic nucleus bombarded by high-energy particles. [1/3 definitions] |
| dysprosium |
a rare-earth metal chemical element of the lanthanide series that has sixty-sixprotons in each nucleus. (symbol: Dy) |
| ectoplasm |
the outer part of the material surrounding the nucleus of a cell. (Cf. endoplasm.) |
| einsteinium |
a synthetic radioactive chemical element that has ninety-nine protons in each nucleus. (symbol: Es) |