Question

identify the formula units for each particle. not all units will be used, some will be used more than once
co₂
fe₂o₃
li
br₂
moles molecules formula units atoms

Explanation:

Step1: Analyze \( \ce{CO_2} \)

\( \ce{CO_2} \) is a covalent compound (molecular compound). The basic unit of a molecular compound is a molecule, and we can also refer to the amount in moles. So \( \ce{CO_2} \) can be associated with moles and molecules.

Step2: Analyze \( \ce{Fe_2O_3} \)

\( \ce{Fe_2O_3} \) is an ionic compound. The basic unit of an ionic compound is a formula unit, and we can also refer to the amount in moles. So \( \ce{Fe_2O_3} \) can be associated with moles and formula units.

Step3: Analyze \( \ce{Li} \)

\( \ce{Li} \) is an element (a metal, atomic solid). The basic unit of an element is an atom, and we can also refer to the amount in moles. So \( \ce{Li} \) can be associated with moles and atoms.

Step4: Analyze \( \ce{Br_2} \)

\( \ce{Br_2} \) is a diatomic molecular element. The basic unit is a molecule (or we can think of individual \( \ce{Br_2} \) molecules, and also in terms of moles). So \( \ce{Br_2} \) can be associated with moles and molecules.

Now, let's make the connections:

• \( \ce{CO_2} \): moles, molecules
• \( \ce{Fe_2O_3} \): moles, formula units
• \( \ce{Li} \): moles, atoms
• \( \ce{Br_2} \): moles, molecules

Answer:

• \( \ce{CO_2} \): moles, molecules
• \( \ce{Fe_2O_3} \): moles, formula units
• \( \ce{Li} \): moles, atoms
• \( \ce{Br_2} \): moles, molecules

(If we are to match each compound to the most appropriate unit type from the given options "moles", "molecules", "formula units", "atoms" for the "identity the formula units for each particle" task, the correct matches are:

\( \ce{CO_2} \): molecules (and moles), \( \ce{Fe_2O_3} \): formula units (and moles), \( \ce{Li} \): atoms (and moles), \( \ce{Br_2} \): molecules (and moles). But since the options are given as separate boxes, the specific connections would be:

\( \ce{CO_2} \) - molecules (and moles), \( \ce{Fe_2O_3} \) - formula units (and moles), \( \ce{Li} \) - atoms (and moles), \( \ce{Br_2} \) - molecules (and moles))

To present the final matching (assuming we have to connect each compound to the best - fit unit from the four options):

• \( \ce{CO_2} \): molecules
• \( \ce{Fe_2O_3} \): formula units
• \( \ce{Li} \): atoms
• \( \ce{Br_2} \): molecules

(And all of them can also be associated with moles as moles is a unit of amount for any substance)

Final Connections:

• \( \ce{CO_2} \) → molecules (and moles)
• \( \ce{Fe_2O_3} \) → formula units (and moles)
• \( \ce{Li} \) → atoms (and moles)
• \( \ce{Br_2} \) → molecules (and moles)