Answer: 3. No displacement, zinc is most reactive.
4. Calcium Chloride, Calcium is most reactive.
5. No displacement, Copper is most reactive
6. No displacement, Calcium is most reactive
7. Hydrogen Oxide, Hydrogen is most reactive
8. Carbon oxide, Carbon is most reactive
9. No displacement, Aluminum is most reactive
10. Potassium Kryptide + Lead, no displacement, Potassium is most reactive.
So they can tell what exact species it is.
The correct answer is a metal atom forms a cation, and a nonmetal atom forms an anion. This is because metals are less electronegative than nonmetals and will therefore give electrons to nonmetals. Atoms that give up electrons will have a positive charge therefore becoming a cation while atoms that accept electrons will have a negative charge therefore becoming an anion.
Ions that have the same charge can't be attracted to each other since it takes a positive and negative charge to cause attractive forces.
A less electronegative atom will transfer electrons to a more electronegative atom.
A metal (cation) can pull electrons from another metal (not an ion) but that does not form an attractive force between the two metals (You will learn more about this when you go over reduction potentials, redox reactions, and electrochemistry).
I hope this helps. Let me know if anything is unclear.
These are formed when, after formation of the first atom, the pi-orbitals of Sulfur and Oxygen align and share another pair of electrons. This occurs between sulfur and both of the oxygen atoms, with each oxygen atom forming one pi-bond.
