Names of the Two Elements Selected

Here's a rubric for assessing the identification of chemical elements, compounds, formulas, and counting the number of each type of atom. You can use this to evaluate how well the answers align with expected responses for chemistry concepts.

Rubric for Identifying Elements and Compounds

| Criteria | Excellent (4) | Good (3) | Fair (2) | Poor (1) | |--------------------------------------|------------------------------------------|-----------------------------------|------------------------------|-----------------------------| | Correct Identification of Elements | All element names are correctly identified. | Most element names are correctly identified. | Some element names are incorrectly identified. | Many element names are incorrect. | | Chemical Formula Accuracy | All chemical formulas are accurately represented. | Most chemical formulas are accurately represented. | Some formulas are inaccurate or incomplete. | Many formulas are incorrect. | | Number of Each Type of Atom | Counts of each type of atom are all correct. | Counts are mostly correct. | Some counts are inaccurate. | Counts are mostly inaccurate. | | Identification as Compound or Element | Correctly identifies all compounds and elements. | Mostly correct identifications. | Some incorrect identifications. | Many incorrect identifications. | | Clarity of Presentation | Information is presented clearly and logically. | Information is mostly clear. | Information is somewhat confusing. | Information is unclear and disorganized. |

Example Answers for Elements and Compounds:

1. Chlorine, Chlorine

   • Chemical Formula: Cl₂
   • Number of Each Type of Atom: 2 Cl
   • Compound or Element: Element

2. Hydrogen, Chlorine

   • Chemical Formula: HCl
   • Number of Each Type of Atom: 1 H, 1 Cl
   • Compound or Element: Compound

3. Sodium, Chlorine

   • Chemical Formula: NaCl
   • Number of Each Type of Atom: 1 Na, 1 Cl
   • Compound or Element: Compound

4. Chlorine, Oxygen

   • Chemical Formula: ClO₂ (or Cl₂O)
   • Number of Each Type of Atom: 1 Cl, 2 O
   • Compound or Element: Compound

5. Hydrogen, Hydrogen

   • Chemical Formula: H₂
   • Number of Each Type of Atom: 2 H
   • Compound or Element: Element

6. Sodium, Hydrogen

   • Chemical Formula: NaH
   • Number of Each Type of Atom: 1 Na, 1 H
   • Compound or Element: Compound

7. Sodium, Sodium

   • Chemical Formula: Na₂
   • Number of Each Type of Atom: 2 Na
   • Compound or Element: Element (or often not listed as a stable diatomic molecule)

8. Sodium, Oxygen

   • Chemical Formula: Na₂O
   • Number of Each Type of Atom: 2 Na, 1 O
   • Compound or Element: Compound

9. Oxygen, Oxygen

   • Chemical Formula: O₂
   • Number of Each Type of Atom: 2 O
   • Compound or Element: Element

This rubric allows for a comprehensive evaluation based on correctness, understanding of chemistry concepts, and the clarity of communication.