Electron Configurations and Periodic Table Reactions

The video tutorial covers electron configurations, focusing on lithium and iron as examples. It explains the concept of backfilling in the d-block and the significance of valence electrons in determining reactivity. The octet rule is introduced, highlighting its role in chemical reactions, particularly between alkali metals and halogens.

What is the electron configuration of lithium?

• 1s1 2s2

• 1s2 2s1

• 1s2 2p1

• 1s2 2s2

Why is the d subshell backfilled in electron configurations?

• Because it is the first shell to be filled

• To maintain a symmetrical atomic structure

• Due to the presence of spaces between previous orbitals

• Because it is the highest energy level

How many electrons are in the outermost shell of iron?

• One

• Two

• Three

• Four

What is the significance of valence electrons?

• They determine the atomic mass

• They are responsible for the color of the element

• They determine the reactivity of the element

• They are not significant

What is the octet rule?

• Atoms aim to have eight neutrons in their nucleus

• Atoms aim to have eight protons in their nucleus

• Atoms aim to have eight electrons in their outermost shell

• Atoms aim to have eight shells

Which elements are exceptions to the octet rule?

• All alkali metals

• All transition metals

• Hydrogen and helium

• All noble gases

What happens when potassium and chlorine are near each other?

• Potassium gains an electron from chlorine

• Chlorine gains an electron from potassium

• They form a covalent bond

• They do not react

Why are alkali metals highly reactive?

• They have a full outer shell

• They want to lose electrons

• They have no electrons in their outer shell

• They want to gain electrons

What is the main characteristic of halogens?

• They have no electrons in their outer shell

• They need one electron to complete their outer shell

• They are inert gases

• They have a full outer shell

What does 'metallic nature' refer to in chemistry?

• The ability to form covalent bonds

• The tendency to lose electrons

• The tendency to gain electrons

• The ability to conduct electricity