Answer: Shielding remains roughly constant while nuclear charge increases.
- A Shielding remains roughly constant while nuclear charge increases
- B Shielding from inner electrons increases faster than nuclear charge
- C The total electron count decreases steadily across the period
- D Atomic mass decreases steadily across the period
Correct answer: A. Shielding remains roughly constant while nuclear charge increases
Explanation: Core electrons provide roughly constant shielding; adding protons increases Zeff and pulls valence electrons in.
The complete modern periodic table (118 elements). Image: Cepheus et al., Public Domain, via Wikimedia Commons.
Concept context
The periodic table organises all 118 elements by atomic number and similar properties. Study periodic trends like atomic radius, ionization energy, and electronegativity, and learn how an element's position predicts its behaviour.
Read the full Classification of Elements and Periodicity in Properties notes →