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Quizzes — Score & Review
Quiz 1 — Atomic Structure & Periodic Table (5 Qs)
1) Which particle defines an element's identity?
2) Which element has configuration 1s² 2s² 2p⁶ ?
3) Atomic radius generally ____ across a period and ____ down a group.
4) Which group contains the noble gases?
5) Which is the best description of an isotope?
Quiz 2 — Stoichiometry & Reactions (5 Qs)
1) Balance: __ H₂ + O₂ → H₂O. Coefficients (smallest whole numbers) are?
2) Molarity of 0.5 mol NaCl in 0.25 L solution is:
3) An oxidation is a ______ of electrons.
4) Endothermic reactions ______ heat and have a positive ΔH.
5) pH of a 1.0 × 10⁻⁴ M H⁺ solution is:
Worked Problems & Regents-style Steps
Example: Stoichiometry (moles → grams)
- Write balanced equation.
- Use mole ratios.
- Convert moles ↔ grams using molar mass.
Problem:
How many grams of CO₂ are produced by 2.00 mol C when burned completely? (C + O₂ → CO₂)