Ch 4: Atomic Structure and Periodic Trends

Question 1

Which principle states that electrons occupy the lowest energy orbitals available?

Answer 1

the Aufbau principle

p. 67

Question 2

Which principle states that electrons in the same subshell occupy available orbitals singly before pairing up?

Answer 2

Hund’s rule

p. 67

Question 3

What principle states that there can be no more than two electrons in any given orbital, and that they must have the opposite spin?

Answer 3

the Pauli exclusion principle

p. 67

Question 4

Because the atom’s positively charged nucleus is attracted to the electrons in the atom, it takes energy to remove an electron. The amount of energy required to remove the least tightly bound electron from an isolated atom is called the atom’s ….

Answer 4

….first ionization energy (IE₁).

Question 5

___ will always be greater than IE₁.

Answer 5

IE₂

p. 79

Question 6

Each filled shell between the nucleus and the valence electrons shields the valence electrons from the full effect if the positively charged protons in the nucleus. This is called….

Answer 6

…nuclear shielding, or the shielding effect.

p. 78

Question 7

What is the formula for Z_eff (effective nuclear charge; the charge “felt” by the valence electrons)?

Answer 7

protons - # ‘core’ electrons

Question 8

As we move from left to right across a period, electrons are being added, but new ______ are not; therefore, the valence electrons are more and more _______ bound to the atom because they feel a greater effective nuclear charge (Z_eff).

Answer 8

shells

tightly

p. 78

Question 9

If we form an ion, the radius will decrease as electrons are removed (bc the ones that are left are drawn in more closely to the nucleus), and the radius will increase as electrons are added. Rank the resulting relative sizes of cations, neutral atoms, and anions.

Answer 9

X⁺ < X < X^-

(cations are smaller than the neutral atom; anions are larger than the neutral atom)

p. 78

Question 10

Which is the smallest ion of these found in the body?

sodium, potassium, or chloride ions

Answer 10

sodium ions are the smallest

(missed question from free practice AAMC exam)

Question 11

In β^- decay, an unstable nucleus contains too many neutrons, and one of these neutrons is converted into a ______.

Answer 11

proton

p. 54

Question 12

In β^- decay, what time of particle is a is ejected?

Answer 12

an electron (aka β^- particle)

p. 54

Question 13

In β^- decay, the atomic number of the resulting daughter nucleus is 1 _______ than the radioactive parent nucleus, but the mass number remains the same. Also, it becomes a ______ since it is losing an electron.

Answer 13

GREATER

(E.g. ¹⁴₆ C → ¹⁴₇ N + ⁰-1 β^-

Question 14

Since alpha and beta decay change the atomic number of an atom, they also change the _______ of the nucleus, but _____ decay does not. This type of decay is simply an expulsion of energy.

Answer 14

identity

gamma

p. 55