One mole is about 6.022*10^23 atoms hence 3.15/6.022 makes 0.523 moles of iron
Elements in the same group tend to have very similar properties (D). This is due to the number of valence electrons each group has.
Answer:
The elements in the alkaline earth metals group; beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra), have two electrons in their outer electronic shell.
Explanation: