As the elements in Group 1 of the Periodic Table are considered in order of increasing acomic number, the atomic radius of each successive element increases. This is primarily
due to an increase in the number of
1) neutrons in the nucleus
3) valence electrons
2) unpeired electrons
4) electron shells
the said state each atom ofan element has two valence electrons. This element

D. is the answer hope that you

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na