In a covalent bond between identical atoms, the electrons are shared between the atoms. If the atoms are not identical, the electron distribution is so that the electrons are closer to one atom than the other. This type of bond is called a(n) covalent bond. Listen to the complete question

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

the population of unionid mussels in the hudson river decreased after zebra mussels were introduced. zebra mussels, a nonnative species, competed with the unionid mussels for food. the zebra mussels were able to outcompete the unionid mussels, allowing the zebra mussel population to increase dramatically over six years. the unionid mussel population decreased due to a lack of food.

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