An Electron and a Positron, Both Essentially at Rest, Annihilate $9.11 \times 10 ^ { - 31 } \mathrm {~kg}$

question 23

Multiple Choice

An electron and a positron, both essentially at rest, annihilate each other, emitting two identical photons in the process. What is the wavelength of these photons? The mass of an electron or positron is $9.11 \times 10 ^ { - 31 } \mathrm {~kg}$ . $\left( h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

• A) \(3.46 \mathrm { pm }\)
• B) \(1.21 \times 10 ^ { - 12 } \mathrm { pm }\)
• C) \(3.07 \mathrm { pm }\)
• D) \(2.42 \mathrm { pm }\)
• E) \(1.73 \mathrm { pm }\)

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Definitions:

Deep Processing

A method of learning in which information is analyzed in a meaningful way, leading to better recall than through shallow processing.

Remembered

Pertaining to having memory or recollection of someone or something

Deep Processing

involves the active manipulation of information to make it meaningful, thus improving its understanding and facilitating its retention.

Craik And Lockhart

Renowned for their Levels of Processing theory, which suggests that memory retention is influenced by the depth of processing, with deeper levels resulting in longer-lasting memory trace.