Science / Biology / Lichens: Autotrophic organisms composed of a fungus (sac or club fungus) and a photosynthetic unicellular organism (e.g., a cyanobacterium or alga) in a symbiotic relationship; are resistant to extremes of cold and drought and can grow in marginal areas such as Arctic tundra.
Science / Periodic Table of Elements / Niobium (Nb): Atomic number: 41, Atomic mass: 92.91 g.mol -1, Electronegativity: unknown, Density: 8.4 g.cm-3 at 20°C, Melting point: 2410 °C, Boiling point: 5100 °C, Vanderwaals radius: 0.143 nm, Ionic radius: MORE
Science / Marine Biology / Epilithic: A term for organisms that live attached to rocks. Latin translation: epi = upon, lith = rock. This term is general to terrestrial and marine habitats, ie. Some lichens are epilithic. MORE
Science / Chemistry / Litmus: A mixture of pigments extracted from certain lichens that turns blue in basic solution and red in acidic solution. MORE