Lines converging at a single center
Lines converging at a single center
Alpha, beta or gamma energy emitted by the decay of atomic nuclei from their radioactive source
A trace radioactive element, symbol, Ra. It occurs in uranium ores
Marine protozoa subject to silica replacement fossilization sound in limestone, shale and other rocks
Rocks transformed by the replacement of eroded or precipitated minerals, by the introduction of newly deposited minerals and while retaining a high percentage of its original form
The time lapse between volcanic eruptions
Having the shape of a kidney
Another term for the shape of the earth surface at a specific point
The layer of rocks, gravel, sand, soil and other matter between surface and bedrock
Ore whose minerals resist separation by initial chemical processes and require further chemical decomposition