Unit 1: Atomic Structure and Properties

An element has two naturally occurring isotopes: isotope A (mass 62.93 u, 69.17%) and isotope B (mass 64.93 u, 30.83%). What is the element?

Which of the following electron configurations represents a ground-state atom of phosphorus (Z = 15)?

Calculate the number of moles in 48.0 g of oxygen gas (O₂). (Molar mass of O = 16.00 g/mol)

Which trend correctly describes ionization energy across a period (left to right)?

Which of the following has the smallest atomic radius?

Which of the following correctly lists the atoms in order of increasing first ionization energy?

The photoelectron spectrum (PES) of an unknown element shows peaks with relative heights of 2, 2, 6, 2, 3. The element is most likely

Which of the following species has the largest atomic/ionic radius?

Which electron configuration represents a ground-state atom of calcium?

The successive ionization energies (in kJ/mol) for an element X are: 578, 1817, 2745, 11578, 14842. Element X is most likely in which group?

Which of the following elements has the highest electronegativity?

The electron configuration of Cu is [Ar] 3d¹⁰ 4s¹ rather than [Ar] 3d⁹ 4s². The best explanation for this is

Isotopes of an element differ in their number of:

The photoelectron spectrum (PES) of an atom shows:

Electron configuration for element with atomic number 26 (Fe) is:

Ionization energy generally increases across a period because:

Coulomb's law in atomic structure explains:

Atomic radius generally decreases across a period because:

The mass spectrometer is used to determine:

Effective nuclear charge ([math]) is: