A new model explaining this mysterious process suggests the core was created as dribs and drabs of iron percolated inward from Earth's lower mantle, according to a study published Oct. 6 in the journal Nature Geoscience. The mantle is the viscous, rocky layer between the crust and Earth's iron core.
Definition of flash card. : a card bearing words, numbers, or pictures that is briefly displayed (as by a teacher to a class) usually as a learning aid.
card game, cards-a game played with playing cards. draw poker, draw-poker in which a player can discard cards and receive substitutes from the dealer; he played only draw and stud. high-low-poker in which the high and low hands split the pot.