To be a useful index fossil, a species must have been rare. true or false

The given statement is False

Index fossils are the fossils that is used as guide or indicator to identify the geologic periods. Index fossils must have a short vertical range and wide geographic distribution and should have evolutionary trends.This fossil need not to be rare to be called as index fossil.

Example: Calico scallop, Scaphites, Inoceramus, Leptodus.

The given statement is False

Index fossils are the fossils that is used as guide or indicator to identify the geologic periods. Index fossils must have a short vertical range and wide geographic distribution and should have evolutionary trends.This fossil need not to be rare to be called as index fossil.

Example: Calico scallop, Scaphites, Inoceramus, Leptodus.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called