Periodic Table

3. Different forms of the same element with varying molecular structures but the same physical state.
4. Elements on the right side of the periodic table that gain electrons to form negative ions (anions).
6. Shielding The effect of inner electrons reducing the nucleus's pull on outer (valence) electrons.
9. The ability of an atom to attract electrons. Atoms with fewer shells and a higher nuclear charge are more electronegative.
10. The positive charge of protons in the nucleus, attracting electrons towards it.
11. Vertical columns in the periodic table where elements share the same number of valence electrons and have increasing atomic radius down the group.
12. Horizontal rows in the periodic table where elements share the same number of electron shells and have increasing nuclear charge.

1. The size of an ion. Cations are smaller than their atoms, and anions are larger due to the gain or loss of electrons.
2. Energy The energy needed to remove an electron from an atom. Atoms with fewer shells and a stronger nucleus require more energy to remove electrons.
5. The distance from the nucleus to the outermost electron shell. It decreases across a period and increases down a group.
7. Elements on the left side of the periodic table that lose electrons to form positive ions (cations).
8. The ability of an element to display metal-like properties, increasing down a group and decreasing across a period.