Gen Chem I Periodic Table and Trends
39 flashcards covering Gen Chem I Periodic Table and Trends for the GENERAL-CHEMISTRY-1 Gen Chem I Topics section.
The topic of the Periodic Table and trends is a foundational component of General Chemistry I, as outlined by the American Chemical Society (ACS) guidelines. This topic includes understanding the organization of the periodic table, the significance of atomic structure, and the trends in properties such as electronegativity, ionization energy, and atomic radius. Mastery of these concepts is crucial for predicting the behavior of elements and compounds in various chemical reactions.
In practice exams and competency assessments, questions often focus on identifying trends within the periodic table, such as how atomic size changes across a period or down a group. Common traps include confusing the trends for ionization energy and electron affinity or misapplying the concepts to specific elements without considering their positions on the table. A frequent oversight is neglecting to account for the role of electron shielding when analyzing trends, which can lead to incorrect conclusions about element reactivity and properties.
Terms (39)
- 01
What is the periodic trend for atomic radius across a period?
Atomic radius decreases across a period from left to right due to increasing nuclear charge which pulls electrons closer to the nucleus (Zumdahl, Chapter 2).
- 02
How does electronegativity change down a group in the periodic table?
Electronegativity decreases down a group as the distance between the nucleus and valence electrons increases, reducing the nucleus's ability to attract electrons (Tro, Chapter 3).
- 03
What is the maximum number of electrons that can occupy the third energy level?
The third energy level can hold a maximum of 18 electrons, as it can contain s, p, and d subshells (Brown LeMay, Chapter 2).
- 04
Which of the following elements has the highest ionization energy: Na, Mg, Al?
Magnesium (Mg) has the highest ionization energy among Na, Mg, and Al due to its higher effective nuclear charge (Tro, Chapter 3).
- 05
What is the trend for ionization energy as you move from top to bottom in a group?
Ionization energy decreases as you move down a group because the outer electrons are farther from the nucleus and are more easily removed (Brown LeMay, Chapter 3).
- 06
Define effective nuclear charge (Zeff).
Effective nuclear charge is the net positive charge experienced by an electron in a multi-electron atom, accounting for both the total nuclear charge and the shielding effect of inner-shell electrons (Zumdahl, Chapter 2).
- 07
How often must the periodic table be updated to reflect new discoveries?
The periodic table is updated as new elements are discovered and confirmed, which occurs irregularly based on scientific advancements (Brown LeMay, Chapter 2).
- 08
What is the trend for metallic character in the periodic table?
Metallic character increases down a group and decreases across a period from left to right (Tro, Chapter 3).
- 09
Which element has the largest atomic radius: Cl, Br, I?
Iodine (I) has the largest atomic radius among Cl, Br, and I because atomic radius increases down a group (Brown LeMay, Chapter 2).
- 10
What is the relationship between electron affinity and atomic size?
Generally, electron affinity becomes more negative as atomic size decreases across a period, indicating a stronger attraction for added electrons (Zumdahl, Chapter 3).
- 11
Under what condition is the ionization energy of an atom measured?
Ionization energy is measured when an atom in the gas phase loses an electron to form a cation (Tro, Chapter 3).
- 12
What happens to the electronegativity of elements as you move from left to right across a period?
Electronegativity increases from left to right across a period due to increasing nuclear charge attracting bonding electrons more strongly (Brown LeMay, Chapter 3).
- 13
Which of the following elements has the lowest electronegativity: Li, Na, K?
Potassium (K) has the lowest electronegativity among Li, Na, and K as electronegativity decreases down a group (Tro, Chapter 3).
- 14
What is the primary reason for the increase in ionization energy across a period?
The primary reason for the increase in ionization energy across a period is the increase in effective nuclear charge, which holds the electrons more tightly (Zumdahl, Chapter 3).
- 15
How does the atomic radius of anions compare to their neutral atoms?
Anions have a larger atomic radius than their neutral atoms due to the increased electron-electron repulsion among added electrons (Brown LeMay, Chapter 2).
- 16
What is the trend for the first ionization energy of the alkali metals?
The first ionization energy of alkali metals decreases down the group as the atomic size increases and the outer electron is further from the nucleus (Tro, Chapter 3).
- 17
Define the term 'periodicity' in the context of the periodic table.
Periodicity refers to the recurring trends that are observed in the properties of elements as you move across periods and down groups in the periodic table (Zumdahl, Chapter 2).
- 18
What is the trend for the size of cations compared to their neutral atoms?
Cations are smaller than their neutral atoms because the loss of electrons reduces electron-electron repulsion and the remaining electrons are drawn closer to the nucleus (Brown LeMay, Chapter 2).
- 19
Which element has the highest electronegativity value?
Fluorine (F) has the highest electronegativity value of all elements, reflecting its strong ability to attract electrons (Tro, Chapter 3).
- 20
What is the trend for the reactivity of nonmetals as you move across a period?
Reactivity of nonmetals generally increases as you move across a period from left to right due to increasing electronegativity (Brown LeMay, Chapter 3).
- 21
How does the shielding effect influence atomic size?
The shielding effect reduces the effective nuclear charge felt by outer electrons, allowing them to be held less tightly and increasing atomic size (Zumdahl, Chapter 2).
- 22
What is the trend for the boiling points of group 1 alkali metals?
The boiling points of group 1 alkali metals decrease down the group due to the weakening of metallic bonds as atomic size increases (Tro, Chapter 3).
- 23
Which of the following elements has the highest ionization energy: O, N, F?
Fluorine (F) has the highest ionization energy among O, N, and F due to its small atomic size and high electronegativity (Brown LeMay, Chapter 3).
- 24
What is the trend in atomic radius for noble gases?
The atomic radius of noble gases increases down the group due to the addition of electron shells (Tro, Chapter 2).
- 25
How does the ionic radius of cations compare to that of anions?
Cations are generally smaller than anions because cations lose electrons, reducing electron-electron repulsion, while anions gain electrons, increasing repulsion (Brown LeMay, Chapter 2).
- 26
What is the trend for the melting points of transition metals?
The melting points of transition metals vary widely but generally increase across the d-block due to strong metallic bonding (Tro, Chapter 3).
- 27
Define the term 'alkali metals'.
Alkali metals are the elements in Group 1 of the periodic table, characterized by having one electron in their outermost shell, which they readily lose to form cations (Zumdahl, Chapter 2).
- 28
What is the trend for the density of alkali metals as you move down the group?
The density of alkali metals generally increases as you move down the group due to increasing atomic mass (Brown LeMay, Chapter 3).
- 29
Which element has the smallest atomic radius: F, Cl, Br?
Fluorine (F) has the smallest atomic radius among F, Cl, and Br due to its higher effective nuclear charge (Tro, Chapter 2).
- 30
What is the trend for the reactivity of metals as you move down a group?
The reactivity of metals increases as you move down a group due to the decrease in ionization energy (Brown LeMay, Chapter 3).
- 31
How does the atomic radius of elements in the same group compare?
Elements in the same group have increasing atomic radii as you move down the group due to the addition of electron shells (Tro, Chapter 2).
- 32
What is the trend for the number of valence electrons across a period?
The number of valence electrons increases from left to right across a period, starting from one valence electron in Group 1 to eight in Group 18 (Brown LeMay, Chapter 2).
- 33
Which group of elements is known for having a full valence shell?
Noble gases are known for having a full valence shell, which makes them largely unreactive (Tro, Chapter 2).
- 34
What is the trend for the atomic radius of elements in the same period?
The atomic radius decreases from left to right across a period due to increasing nuclear charge (Brown LeMay, Chapter 2).
- 35
Define 'metalloids' in the context of the periodic table.
Metalloids are elements that have properties intermediate between metals and nonmetals, typically found along the zig-zag line on the periodic table (Tro, Chapter 2).
- 36
What is the trend for the first ionization energy of the halogens?
The first ionization energy of halogens increases up the group as atomic size decreases (Brown LeMay, Chapter 3).
- 37
How does the reactivity of halogens change down the group?
The reactivity of halogens decreases down the group due to the increasing atomic size and decreasing electronegativity (Tro, Chapter 3).
- 38
What is the general trend for the size of atoms as you move from left to right across a period?
Atoms generally decrease in size as you move from left to right across a period due to increased nuclear charge attracting electrons more strongly (Brown LeMay, Chapter 2).
- 39
What is the trend for the ionization energy of transition metals?
The ionization energy of transition metals varies but is generally higher than that of alkali and alkaline earth metals due to their d-electron configurations (Tro, Chapter 3).