AP Chemistry Flashcards: Lewis Diagrams

What this deck covers

This deck focuses on Lewis Diagrams, 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: What is the Lewis Diagram for sulfur hexafluoride ($SF_6$)?

Answer: F-S-F with four additional F atoms bonded to S. Octahedral structure utilizing sulfur's expanded octet.

Flashcard 2: What is the Lewis Diagram for ethylene ($C_2H_4$)?

Answer: H-C=C-H with additional H atoms bonded to each C. Planar molecule with carbon-carbon double bond.

Flashcard 3: How many lone pairs are on the oxygen in water's Lewis Diagram?

Answer: Two lone pairs. Oxygen has 6 valence electrons, forms 2 bonds, leaves 4 as lone pairs.

Flashcard 4: What is the Lewis Diagram for phosphine ($PH_3$)?

Answer: H-P-H with one lone pair on P and an additional H. Trigonal pyramidal shape with phosphorus as central atom.

Flashcard 5: What does a triple bond indicate in a Lewis Diagram?

Answer: Three pairs of shared electrons. Triple bonds involve six electrons in three pairs.

Flashcard 6: How are lone pairs visually represented in Lewis Diagrams?

Answer: As pairs of dots around the atom. Dots show unshared electrons around atomic symbols.

Flashcard 7: State the Lewis Diagram for hydrogen chloride ($HCl$).

Answer: H-Cl with three lone pairs on Cl. Polar molecule with chlorine having three lone pairs.

Flashcard 8: How do you denote resonance in Lewis Diagrams?

Answer: By using double-headed arrows between structures. Shows electron delocalization across multiple structures.

Flashcard 9: What symbol is used for a lone pair of electrons in Lewis Diagrams?

Answer: Dots around the atom. Two dots represent an unshared electron pair.

Flashcard 10: How are expanded octets represented in Lewis Diagrams?

Answer: With more than eight electrons around the central atom. Shows atoms with more than 8 valence electrons.

Flashcard 11: How many lone pairs are on the nitrogen in ammonia's Lewis Diagram?

Answer: One lone pair. Nitrogen uses three electrons for bonds, two remain as lone pair.

Flashcard 12: What does a triple bond indicate in a Lewis Diagram?

Answer: Three pairs of shared electrons. Triple bonds involve six electrons in three pairs.

Flashcard 13: How are lone pairs visually represented in Lewis Diagrams?

Answer: As pairs of dots around the atom. Dots show unshared electrons around atomic symbols.

Flashcard 14: Identify the Lewis Diagram for ozone ($O_3$).

Answer: O=O-O with one lone pair on the central O and two on the others. Bent molecule showing resonance between oxygen atoms.

Flashcard 15: How do you denote resonance in Lewis Diagrams?

Answer: By using double-headed arrows between structures. Shows electron delocalization across multiple structures.

Flashcard 16: How do you represent a single bond in a Lewis Diagram?

Answer: With a single line between two atoms. One line equals one electron pair shared between atoms.

Flashcard 17: How many lone pairs are on the nitrogen in ammonia's Lewis Diagram?

Answer: One lone pair. Nitrogen uses three electrons for bonds, two remain as lone pair.

Flashcard 18: What is the Lewis Diagram for a nitrogen molecule ($N_2$)?

Answer: N≡N. Triple bond forms when nitrogen atoms share three electron pairs.

Flashcard 19: What is the purpose of a Lewis Diagram?

Answer: To show the bonding between atoms and lone pairs of electrons. Visualizes electron distribution and chemical bonding patterns.

Flashcard 20: What does a triple bond indicate in a Lewis Diagram?

Answer: Three pairs of shared electrons. Triple bonds involve six electrons in three pairs.

Flashcard 21: What symbol is used for a lone pair of electrons in Lewis Diagrams?

Answer: Dots around the atom. Two dots represent an unshared electron pair.

Flashcard 22: Identify the Lewis Diagram for a diatomic oxygen molecule.

Answer: :O::O: or O=O. Double bond between oxygens with two lone pairs each.

Flashcard 23: How many covalent bonds does nitrogen typically form?

Answer: Three covalent bonds. Uses three of its five valence electrons for bonding.

Flashcard 24: What is the Lewis Diagram for formaldehyde ($CH_2O$)?

Answer: H-C=O with an additional H on C and two lone pairs on O. Planar molecule with carbon-oxygen double bond.

Flashcard 25: What is the Lewis Diagram for hydrogen peroxide ($H_2O_2$)?

Answer: H-O-O-H with two lone pairs on each O. Chain structure with oxygen-oxygen single bond.

Flashcard 26: State the Lewis Diagram for hydrogen chloride ($HCl$).

Answer: H-Cl with three lone pairs on Cl. Polar molecule with chlorine having three lone pairs.

Flashcard 27: What is the Lewis Diagram for carbon dioxide ($CO_2$)?

Answer: O=C=O. Linear molecule with carbon forming two double bonds.

Flashcard 28: How do you represent a single bond in a Lewis Diagram?

Answer: With a single line between two atoms. One line equals one electron pair shared between atoms.

Flashcard 29: What is the typical valence electron count for nitrogen in Lewis Diagrams?

Answer: Five. Nitrogen is in group 15 of the periodic table.

Flashcard 30: What is the Lewis Diagram for phosphine ($PH_3$)?

Answer: H-P-H with one lone pair on P and an additional H. Trigonal pyramidal shape with phosphorus as central atom.

Flashcard 31: How many lone pairs are on the oxygen in water's Lewis Diagram?

Answer: Two lone pairs. Oxygen has 6 valence electrons, forms 2 bonds, leaves 4 as lone pairs.

Flashcard 32: Identify the Lewis Diagram for sulfur dioxide ($SO_2$).

Answer: O=S-O with one lone pair on S and two on each O. Bent structure due to lone pair repulsion on sulfur.

Flashcard 33: Identify the Lewis Diagram for a diatomic oxygen molecule.

Answer: :O::O: or O=O. Double bond between oxygens with two lone pairs each.

Flashcard 34: Identify the Lewis Diagram for sulfur dioxide ($SO_2$).

Answer: O=S-O with one lone pair on S and two on each O. Bent structure due to lone pair repulsion on sulfur.

Flashcard 35: How are lone pairs visually represented in Lewis Diagrams?

Answer: As pairs of dots around the atom. Dots show unshared electrons around atomic symbols.

Flashcard 36: What is the significance of the octet rule in Lewis Diagrams?

Answer: Atoms tend to have eight electrons in their valence shell. Stable electron configuration for most main group elements.

Flashcard 37: State the Lewis Diagram for dichloromethane ($CH_2Cl_2$).

Answer: H-C-Cl with an additional H and Cl bonded to C. Tetrahedral carbon with two hydrogen and two chlorine atoms.

Flashcard 38: State the Lewis Diagram for methane ($CH_4$).

Answer: H-C-H with two additional H atoms bonded to C. Tetrahedral structure with carbon bonded to four hydrogens.

Flashcard 39: How many bonds are typically formed by oxygen in Lewis Diagrams?

Answer: Two bonds. Oxygen typically forms two covalent bonds to complete octet.

Flashcard 40: What is the purpose of a Lewis Diagram?

Answer: To show the bonding between atoms and lone pairs of electrons. Visualizes electron distribution and chemical bonding patterns.

Flashcard 41: What is the Lewis Diagram for phosphine ($PH_3$)?

Answer: H-P-H with one lone pair on P and an additional H. Trigonal pyramidal shape with phosphorus as central atom.

Flashcard 42: What is the significance of the octet rule in Lewis Diagrams?

Answer: Atoms tend to have eight electrons in their valence shell. Stable electron configuration for most main group elements.

Flashcard 43: How do you represent a shared electron pair in a Lewis Diagram?

Answer: With a line between the two atoms. Line notation represents covalent bonding electrons.

Flashcard 44: State the Lewis Diagram for methane ($CH_4$).

Answer: H-C-H with two additional H atoms bonded to C. Tetrahedral structure with carbon bonded to four hydrogens.

Flashcard 45: How many valence electrons does carbon have in a Lewis Diagram?

Answer: Four. Carbon is in group 14, giving it 4 valence electrons.

Flashcard 46: State the Lewis Diagram for acetylene ($C_2H_2$).

Answer: H-C≡C-H. Linear molecule with carbon-carbon triple bond.

Flashcard 47: What is the Lewis Diagram for carbon dioxide ($CO_2$)?

Answer: O=C=O. Linear molecule with carbon forming two double bonds.

Flashcard 48: What is the typical valence electron count for nitrogen in Lewis Diagrams?

Answer: Five. Nitrogen is in group 15 of the periodic table.

Flashcard 49: What is the Lewis Diagram for nitric oxide ($NO$)?

Answer: N=O with one lone pair on N and two on O. Radical molecule with unpaired electron on nitrogen.

Flashcard 50: What is the Lewis Diagram for nitric oxide ($NO$)?

Answer: N=O with one lone pair on N and two on O. Radical molecule with unpaired electron on nitrogen.

Flashcard 51: Identify the Lewis Diagram for ammonia ($NH_3$).

Answer: H-N-H with one lone pair on N and an additional H. Trigonal pyramidal with nitrogen forming three bonds.

Flashcard 52: How do you represent a shared electron pair in a Lewis Diagram?

Answer: With a line between the two atoms. Line notation represents covalent bonding electrons.

Flashcard 53: Which element is represented by the symbol 'Cl' in a Lewis Diagram?

Answer: Chlorine. Cl is the chemical symbol for this halogen element.

Flashcard 54: Identify the Lewis Diagram for ammonia ($NH_3$).

Answer: H-N-H with one lone pair on N and an additional H. Trigonal pyramidal with nitrogen forming three bonds.

Flashcard 55: What does each line in a Lewis Diagram represent?

Answer: A pair of shared electrons. Each line shows a covalent bond of two electrons.

Flashcard 56: What symbol is used for a lone pair of electrons in Lewis Diagrams?

Answer: Dots around the atom. Two dots represent an unshared electron pair.

Flashcard 57: How many lone pairs are on the nitrogen in ammonia's Lewis Diagram?

Answer: One lone pair. Nitrogen uses three electrons for bonds, two remain as lone pair.

Flashcard 58: Identify the Lewis Diagram for ozone ($O_3$).

Answer: O=O-O with one lone pair on the central O and two on the others. Bent molecule showing resonance between oxygen atoms.

Flashcard 59: How many bonds are typically formed by oxygen in Lewis Diagrams?

Answer: Two bonds. Oxygen typically forms two covalent bonds to complete octet.

Flashcard 60: How do you represent a single bond in a Lewis Diagram?

Answer: With a single line between two atoms. One line equals one electron pair shared between atoms.

Flashcard 61: How many bonds are typically formed by oxygen in Lewis Diagrams?

Answer: Two bonds. Oxygen typically forms two covalent bonds to complete octet.

Flashcard 62: Identify the Lewis Diagram for boron trifluoride ($BF_3$).

Answer: F-B-F with one additional F atom bonded to B. Trigonal planar with boron having incomplete octet.

Flashcard 63: State the Lewis Diagram for acetylene ($C_2H_2$).

Answer: H-C≡C-H. Linear molecule with carbon-carbon triple bond.

Flashcard 64: How many covalent bonds does nitrogen typically form?

Answer: Three covalent bonds. Uses three of its five valence electrons for bonding.

Flashcard 65: What is the Lewis Diagram for ethylene ($C_2H_4$)?

Answer: H-C=C-H with additional H atoms bonded to each C. Planar molecule with carbon-carbon double bond.

Flashcard 66: What is the Lewis Diagram for hydrogen peroxide ($H_2O_2$)?

Answer: H-O-O-H with two lone pairs on each O. Chain structure with oxygen-oxygen single bond.

Flashcard 67: Which element can exceed the octet rule in Lewis Diagrams?

Answer: Phosphorus. Third period elements can use d orbitals for bonding.

Flashcard 68: How do you denote resonance in Lewis Diagrams?

Answer: By using double-headed arrows between structures. Shows electron delocalization across multiple structures.

Flashcard 69: What is the Lewis Diagram for carbon dioxide ($CO_2$)?

Answer: O=C=O. Linear molecule with carbon forming two double bonds.

Flashcard 70: Which element can exceed the octet rule in Lewis Diagrams?

Answer: Phosphorus. Third period elements can use d orbitals for bonding.

Flashcard 71: What is the Lewis Diagram for ethylene ($C_2H_4$)?

Answer: H-C=C-H with additional H atoms bonded to each C. Planar molecule with carbon-carbon double bond.

Flashcard 72: What is the Lewis Diagram for a nitrogen molecule ($N_2$)?

Answer: N≡N. Triple bond forms when nitrogen atoms share three electron pairs.

Flashcard 73: State the Lewis Diagram for acetylene ($C_2H_2$).

Answer: H-C≡C-H. Linear molecule with carbon-carbon triple bond.

Flashcard 74: Which element is represented by the symbol 'Cl' in a Lewis Diagram?

Answer: Chlorine. Cl is the chemical symbol for this halogen element.

Flashcard 75: How do you represent a shared electron pair in a Lewis Diagram?

Answer: With a line between the two atoms. Line notation represents covalent bonding electrons.

Flashcard 76: Identify the Lewis Diagram for a diatomic oxygen molecule.

Answer: :O::O: or O=O. Double bond between oxygens with two lone pairs each.

Flashcard 77: What is the Lewis Diagram for sulfur hexafluoride ($SF_6$)?

Answer: F-S-F with four additional F atoms bonded to S. Octahedral structure utilizing sulfur's expanded octet.

Flashcard 78: How are double bonds represented in Lewis Diagrams?

Answer: With two parallel lines between the bonded atoms. Two parallel lines indicate four shared electrons.

Flashcard 79: What is the Lewis Diagram for sulfur hexafluoride ($SF_6$)?

Answer: F-S-F with four additional F atoms bonded to S. Octahedral structure utilizing sulfur's expanded octet.

Flashcard 80: State the Lewis Diagram for dichloromethane ($CH_2Cl_2$).

Answer: H-C-Cl with an additional H and Cl bonded to C. Tetrahedral carbon with two hydrogen and two chlorine atoms.

Flashcard 81: What is the Lewis Diagram for nitric oxide ($NO$)?

Answer: N=O with one lone pair on N and two on O. Radical molecule with unpaired electron on nitrogen.

Flashcard 82: What is the significance of the octet rule in Lewis Diagrams?

Answer: Atoms tend to have eight electrons in their valence shell. Stable electron configuration for most main group elements.

Flashcard 83: What does each line in a Lewis Diagram represent?

Answer: A pair of shared electrons. Each line shows a covalent bond of two electrons.

Flashcard 84: What is the typical valence electron count for nitrogen in Lewis Diagrams?

Answer: Five. Nitrogen is in group 15 of the periodic table.

Flashcard 85: Identify the Lewis Diagram for ozone ($O_3$).

Answer: O=O-O with one lone pair on the central O and two on the others. Bent molecule showing resonance between oxygen atoms.

Flashcard 86: How are expanded octets represented in Lewis Diagrams?

Answer: With more than eight electrons around the central atom. Shows atoms with more than 8 valence electrons.

Flashcard 87: What is the Lewis Diagram for formaldehyde ($CH_2O$)?

Answer: H-C=O with an additional H on C and two lone pairs on O. Planar molecule with carbon-oxygen double bond.

Flashcard 88: Find the error in this Lewis Diagram for water: H-O-H

Answer: Missing two lone pairs on the oxygen. Oxygen needs two lone pairs to complete its octet.

Flashcard 89: Identify the Lewis Diagram for sulfur dioxide ($SO_2$).

Answer: O=S-O with one lone pair on S and two on each O. Bent structure due to lone pair repulsion on sulfur.

Flashcard 90: State the Lewis Diagram for dichloromethane ($CH_2Cl_2$).

Answer: H-C-Cl with an additional H and Cl bonded to C. Tetrahedral carbon with two hydrogen and two chlorine atoms.

Flashcard 91: What is the Lewis Diagram for a nitrogen molecule ($N_2$)?

Answer: N≡N. Triple bond forms when nitrogen atoms share three electron pairs.

Flashcard 92: What is the Lewis Diagram for formaldehyde ($CH_2O$)?

Answer: H-C=O with an additional H on C and two lone pairs on O. Planar molecule with carbon-oxygen double bond.

Flashcard 93: Identify the Lewis Diagram for carbon tetrachloride ($CCl_4$).

Answer: Cl-C-Cl with two additional Cl atoms bonded to C. Tetrahedral structure with carbon bonded to four chlorines.

Flashcard 94: What is the purpose of a Lewis Diagram?

Answer: To show the bonding between atoms and lone pairs of electrons. Visualizes electron distribution and chemical bonding patterns.

Flashcard 95: State the Lewis Diagram for methane ($CH_4$).

Answer: H-C-H with two additional H atoms bonded to C. Tetrahedral structure with carbon bonded to four hydrogens.

Flashcard 96: How many covalent bonds does nitrogen typically form?

Answer: Three covalent bonds. Uses three of its five valence electrons for bonding.

Flashcard 97: Identify the Lewis Diagram for carbon tetrachloride ($CCl_4$).

Answer: Cl-C-Cl with two additional Cl atoms bonded to C. Tetrahedral structure with carbon bonded to four chlorines.

Flashcard 98: Which element is represented by the symbol 'Cl' in a Lewis Diagram?

Answer: Chlorine. Cl is the chemical symbol for this halogen element.

Flashcard 99: How are double bonds represented in Lewis Diagrams?

Answer: With two parallel lines between the bonded atoms. Two parallel lines indicate four shared electrons.

Flashcard 100: What does each line in a Lewis Diagram represent?

Answer: A pair of shared electrons. Each line shows a covalent bond of two electrons.