Chem Exam 2

Why is electron spin important when writing electron configurations?

because of Pauli exclusion principle.

When filling degenerate orbitals, electrons fill them singly first, with parallel spins. This way of filling orbitals known as

Hund's rule.

Give the number of core electrons for Br-.

28

What is the estimated effective nuclear charge, Zeff, experienced by an electron in a 3p orbital of a chlorine atom?

7

The systematic pattern for filling up the electron configuration, from low energy to high energy, for an element is called the

the Aufbau principle.

No two electrons in an atom can have the same four quantum numbers is known as

the Pauli exclusion principle.

Give the electron configuration for N.

1s2 2s2 2p3

Which statement is true about electron shielding of nuclear charge?

Core electrons efficiently shield outermost electrons from nuclear charge.

Define electron affinity.

Electron affinity is the energy associated with the gaining of an electron by an atom in the gaseous state.

Identify the species that has the smallest radius.

P+3

What is the difference between first ionization energy and second ionization energy?

The second IE is always greater than the first IE

The basic principle in balancing a chemical equation is to ______.

have the same number of atoms of each element in the reactants and in the products

What is the general trend in first ionization energy as you move down a column in the periodic table?

ionization energy decreases

What is the general trend in first ionization energy as you move across a row in the periodic table?

ionization energy increases

The element that corresponds to the electron configuration 1s2 2s2 2p6 3s2 is

magnesium.

The element that corresponds to the electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d5 is

manganese.

Give the set of four quantum numbers that could represent the last electron added (using the Aufbau principle) to the Kr atom.

n = 4, l = 1, ml = 1, ms = -12

What are degenerate orbitals?

orbitals of the same energy

What is ionization energy?

the energy required to remove an electron from the atom or ion in the gaseous state