A Collection of Atoms Has 20% of the Sample in a State

question 2

Multiple Choice

A collection of atoms has 20% of the sample in a state above the ground state. If these emit coherent radiation, what is the wavelength of the laser light produced? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

• A) 210 nm
• B) 91 nm
• C) 340 nm
• D) 34 nm

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Definitions:

Closing Entries

Journal entries made at the end of an accounting period to transfer temporary account balances to permanent accounts, thus preparing the books for the next period.

Unadjusted Trial Balance

A preliminary list of all accounts and their balances before any adjusting entries are made, used to verify the equality of debits and credits.

Closing Entry

A closing entry is an accounting action that transfers the balances of temporary accounts to permanent accounts, thereby resetting the temporary accounts to zero for the start of the next accounting period.

Expense Accounts

Accounts that track the costs incurred by a business in its operational activities, which are then used to calculate net income by subtracting them from revenues.