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.
Section 1: What is Flash? Flash is a multimedia software originally designed by Macromedia that has spawned a whole new genre of websites with fast, vector-based animation (uses mathematical equations to ensure they scale correctly based on monitor size) and sound. 1.1 A little history lesson.