Classification of Elements & Periodicity in Properties Flashcards for NEET — 20 cards

First 8 of 20 Classification of Elements & Periodicity in Properties flashcards

Read the question, answer it in your head, then open the answer to check yourself.

1. Card 1 of 20

   Write the IUPAC name and symbol for the element with atomic number 119.

   Hint: 1 = un, 1 = un, 9 = enn

   Show answerHide answer

   Answer

   Name: Ununennium Symbol: Uue

2. Card 2 of 20

   What is the general outer electronic configuration for the d-block (Transition) elements?

   Hint: They fill the inner d-orbitals.

   Show answerHide answer

   Answer

   $(n-1)d^{1-10} ns^{0-2}$

3. Card 3 of 20

   What is the fundamental difference between Mendeleev's Periodic Law and the Modern Periodic Law?

   Hint: Properties are a periodic function of their...

   Show answerHide answer

   Answer

   Mendeleev's law is based on Atomic Mass, whereas the Modern Periodic law (Moseley) is based on Atomic Number.

4. Card 4 of 20

   Why are elements of Group 12 (Zn, Cd, Hg) generally NOT considered true transition elements?

   Hint: Transition implies incomplete/partially filled d-orbitals.

   Show answerHide answer

   Answer

   Because they have completely filled d-orbitals ($d^{10}$) in their ground state as well as in their common oxidation states.

5. Card 5 of 20

   How do you determine the Period and Group of an element from its electronic configuration?

   Hint: Period is the outermost shell.

   Show answerHide answer

   Answer

   Period = The highest principal quantum number ($n$) of the valence shell. Group for s-block = number of valence electrons. Group for p-block = $10 +$ number of valence electrons. Group for d-block = number of electrons in $(n-1)d +$ number of electrons in $ns$.

6. Card 6 of 20

   Explain the general trend of Atomic Radius across a period and down a group.

   Hint: Z-eff dominates across; Principal Quantum Number (n) dominates down.

   Show answerHide answer

   Answer

   Across a period (left to right): Decreases (due to increasing effective nuclear charge, $Z_{eff}$, pulling electrons closer). Down a group (top to bottom): Increases (due to the addition of new principal shells, outweighing the increase in nuclear charge).

7. Card 7 of 20

   Define Ionization Enthalpy ($\Delta_i H$). Is it an endothermic or exothermic process?

   Hint: You have to supply energy to overcome the nucleus's attraction.

   Show answerHide answer

   Answer

   The minimum amount of energy required to remove the most loosely bound electron from an isolated gaseous atom in its ground state. It is always an endothermic process ($\Delta_i H$ is positive).

8. Card 8 of 20

   Why is the first ionization enthalpy of Nitrogen greater than that of Oxygen, breaking the general trend across Period 2?

   Hint: Half-filled and fully-filled subshells have extra exchange energy and symmetry.

   Show answerHide answer

   Answer