AP Chemistry Flashcards: Periodic Trends

What this deck covers

This deck focuses on Periodic Trends, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Which element has the lowest electronegativity?

Answer: Francium. Largest atomic size with lowest nuclear charge effect.

Flashcard 2: What is the shielding effect?

Answer: Reduction in effective nuclear charge by inner electrons. Core electrons block valence electrons from nuclear attraction.

Flashcard 3: What is the trend for oxidation states in transition metals?

Answer: Varies widely, often multiple oxidation states. D-electrons can be lost in different combinations.

Flashcard 4: How does metallic character change across a period?

Answer: Metallic character decreases across a period. Atoms lose electrons less easily with higher nuclear charge.

Flashcard 5: What is the trend for reactivity in alkali metals down a group?

Answer: Reactivity increases down the group. Larger size makes valence electrons easier to lose.

Flashcard 6: What is the trend for metallic character in transition metals?

Answer: Varies slightly but generally high. D-electrons provide consistent metallic bonding across period.

Flashcard 7: What is the trend for ionic radius across a period?

Answer: Ionic radius decreases across a period. Higher nuclear charge contracts electron clouds around ions.

Flashcard 8: What is the trend for electronegativity across a period?

Answer: Electronegativity increases across a period. Higher nuclear charge increases attraction for electrons.

Flashcard 9: What is the trend for metallic character in transition metals?

Answer: Varies slightly but generally high. D-electrons provide consistent metallic bonding across period.

Flashcard 10: Which element has the highest ionization energy?

Answer: Helium. Small size and high nuclear charge resist electron removal.

Flashcard 11: What is the trend for boiling points across a period?

Answer: Boiling points vary; metals generally increase. Stronger metallic bonding with more valence electrons.

Flashcard 12: What is the trend for electron affinity down a group?

Answer: Electron affinity becomes less negative down a group. Increased size and shielding reduce attraction for electrons.

Flashcard 13: What is the trend for melting points in alkali metals?

Answer: Melting points decrease down the group. Weaker metallic bonding with larger atomic size.

Flashcard 14: What is the trend for ionic radius down a group?

Answer: Ionic radius increases down a group. Additional electron shells increase ionic size.

Flashcard 15: What is the trend for boiling points across a period?

Answer: Boiling points vary; metals generally increase. Stronger metallic bonding with more valence electrons.

Flashcard 16: What is the trend for atomic radius across a period?

Answer: Atomic radius decreases across a period. Increasing nuclear charge pulls electrons closer with same shielding.

Flashcard 17: What is the general trend of density across a period?

Answer: Density generally increases across a period. More protons and electrons in smaller volume.

Flashcard 18: What is the trend for oxidation states in transition metals?

Answer: Varies widely, often multiple oxidation states. D-electrons can be lost in different combinations.

Flashcard 19: Which group has the highest ionization energies?

Answer: Noble gases. Stable electron configurations resist electron removal.

Flashcard 20: Which group has elements with zero electronegativity?

Answer: Noble gases. Electronegativity undefined for unreactive noble gases.

Flashcard 21: How does metallic character change down a group?

Answer: Metallic character increases down a group. Larger size makes valence electrons easier to remove.

Flashcard 22: What is the trend for melting points in alkali metals?

Answer: Melting points decrease down the group. Weaker metallic bonding with larger atomic size.

Flashcard 23: Why do noble gases have low reactivity?

Answer: Noble gases have a full valence shell. Complete octets provide maximum stability and low reactivity.

Flashcard 24: What is the trend for electron affinity across a period?

Answer: Electron affinity becomes more negative across a period. Atoms more readily accept electrons due to higher nuclear charge.

Flashcard 25: What is the general trend of density across a period?

Answer: Density generally increases across a period. More protons and electrons in smaller volume.

Flashcard 26: What is the trend for covalent radius across a period?

Answer: Covalent radius decreases across a period. Same trend as atomic radius due to nuclear charge.

Flashcard 27: How does metallic character change across a period?

Answer: Metallic character decreases across a period. Atoms lose electrons less easily with higher nuclear charge.

Flashcard 28: Which element has the smallest atomic radius?

Answer: Helium. Highest nuclear charge with no shielding electrons.

Flashcard 29: What is the trend for electron affinity in noble gases?

Answer: Noble gases have positive or zero electron affinity. Stable electron configurations resist gaining electrons.

Flashcard 30: What is the trend for atomic size across a period?

Answer: Atomic size decreases across a period. Same as atomic radius due to increased nuclear charge.

Flashcard 31: What is the trend for covalent radius across a period?

Answer: Covalent radius decreases across a period. Same trend as atomic radius due to nuclear charge.

Flashcard 32: What is the shielding effect?

Answer: Reduction in effective nuclear charge by inner electrons. Core electrons block valence electrons from nuclear attraction.

Flashcard 33: What is the trend for electron affinity in noble gases?

Answer: Noble gases have positive or zero electron affinity. Stable electron configurations resist gaining electrons.

Flashcard 34: How does ionization energy change across a period?

Answer: Ionization energy increases across a period. Higher nuclear charge makes it harder to remove electrons.

Flashcard 35: What is the trend for ionic radius down a group?

Answer: Ionic radius increases down a group. Additional electron shells increase ionic size.

Flashcard 36: What is the trend for ionization energy in noble gases?

Answer: High ionization energy due to full valence shell. Stable electron configurations require maximum energy to ionize.

Flashcard 37: Which group has elements with zero electronegativity?

Answer: Noble gases. Electronegativity undefined for unreactive noble gases.

Flashcard 38: What is the trend for electronegativity down a group?

Answer: Electronegativity decreases down a group. Increased distance reduces attraction for bonding electrons.

Flashcard 39: How does ionization energy change down a group?

Answer: Ionization energy decreases down a group. Increased shielding and distance reduce nuclear attraction.

Flashcard 40: Which block of elements has the highest electronegativity?

Answer: P-block. Contains fluorine and other highly electronegative nonmetals.

Flashcard 41: What causes the atomic radius to decrease across a period?

Answer: Increased nuclear charge pulls electrons closer. More protons attract electrons more strongly.

Flashcard 42: What is the trend for covalent radius down a group?

Answer: Covalent radius increases down a group. Same trend as atomic radius due to electron shells.

Flashcard 43: What is the trend for atomic radius down a group?

Answer: Atomic radius increases down a group. Additional electron shells increase distance from nucleus.

Flashcard 44: Which element has the largest atomic radius?

Answer: Cesium. Largest number of electron shells among all elements.

Flashcard 45: How does metallic character change down a group?

Answer: Metallic character increases down a group. Larger size makes valence electrons easier to remove.

Flashcard 46: What is the trend for density down a group?

Answer: Density generally increases down a group. More massive atoms with larger size pack more densely.

Flashcard 47: What is the trend for ionic radius across a period?

Answer: Ionic radius decreases across a period. Higher nuclear charge contracts electron clouds around ions.

Flashcard 48: What is the trend for ionization energy in noble gases?

Answer: High ionization energy due to full valence shell. Stable electron configurations require maximum energy to ionize.

Flashcard 49: What is the trend for electronegativity across a period?

Answer: Electronegativity increases across a period. Higher nuclear charge increases attraction for electrons.

Flashcard 50: What is electron shielding?

Answer: Inner electrons block outer electrons from nuclear charge. Core electrons reduce effective nuclear charge on outer electrons.

Flashcard 51: Which element has the highest electronegativity?

Answer: Fluorine. Highest nuclear charge with smallest atomic size.

Flashcard 52: What trend is observed in melting points across a period?

Answer: Melting points vary but generally increase across metals. More bonding electrons and smaller size strengthen bonds.

Flashcard 53: What trend is observed in melting points across a period?

Answer: Melting points vary but generally increase across metals. More bonding electrons and smaller size strengthen bonds.

Flashcard 54: Which element has the lowest electronegativity?

Answer: Francium. Largest atomic size with lowest nuclear charge effect.

Flashcard 55: What is the trend for density down a group?

Answer: Density generally increases down a group. More massive atoms with larger size pack more densely.

Flashcard 56: Why do noble gases have low reactivity?

Answer: Noble gases have a full valence shell. Complete octets provide maximum stability and low reactivity.

Flashcard 57: Which element has the largest atomic radius?

Answer: Cesium. Largest number of electron shells among all elements.

Flashcard 58: What is the trend of metallic nature in the periodic table?

Answer: Increases down a group, decreases across a period. Larger atoms lose electrons more easily than smaller ones.

Flashcard 59: Which element has the smallest atomic radius?

Answer: Helium. Highest nuclear charge with no shielding electrons.

Flashcard 60: Which block of elements has the highest electronegativity?

Answer: P-block. Contains fluorine and other highly electronegative nonmetals.

Flashcard 61: What is the trend for atomic size down a group?

Answer: Atomic size increases down a group. Same as atomic radius due to additional electron shells.

Flashcard 62: What is the trend for reactivity in halogens down a group?

Answer: Reactivity decreases down the group. Smaller size holds electrons more tightly.

Flashcard 63: What is the trend for reactivity in alkali metals down a group?

Answer: Reactivity increases down the group. Larger size makes valence electrons easier to lose.

Flashcard 64: Which element has the highest ionization energy?

Answer: Helium. Small size and high nuclear charge resist electron removal.

Flashcard 65: What is the trend for electron affinity down a group?

Answer: Electron affinity becomes less negative down a group. Increased size and shielding reduce attraction for electrons.