MTTC Chemistry Flashcards

What is the maximum number of electrons that can occupy the second energy level (n=2) of an atom?

Answer: 8

The second energy level holds a maximum of 8 electrons distributed across the 2s² and 2p⁶ subshells.

Which element has the highest electronegativity on the Pauling scale?

Answer: Fluorine

Fluorine has the highest electronegativity (4.0 on the Pauling scale) of all elements.

What type of bond forms when electrons are shared unequally between two atoms of different electronegativities?

Answer: Polar covalent bond

A polar covalent bond results from unequal electron sharing due to an electronegativity difference between bonded atoms.

Which quantum number determines the shape of an electron orbital?

Answer: Angular momentum quantum number (l)

The angular momentum quantum number (l) determines orbital shape, distinguishing s, p, d, and f orbitals.

Which pair of atoms represents isotopes of the same element?

Answer: ¹²C and ¹⁴C

¹²C and ¹⁴C are isotopes because both are carbon atoms (same proton count) but differ in neutron count.

What is the correct electron configuration for a neutral iron atom (Fe, atomic number 26)?

Answer: [Ar] 3d⁶ 4s²

Iron's configuration is [Ar] 3d⁶ 4s², as the 4s subshell fills before 3d in the aufbau order.

Which statement best describes the trend in atomic radius across a period (left to right) in the periodic table?

Answer: Atomic radius decreases because nuclear charge increases without adding new energy levels

Across a period, increasing nuclear charge pulls electrons closer without adding new energy levels, decreasing atomic radius.