If the Momentum of an Electron Is $1.95 \times 10 ^ { - 27 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$

Multiple Choice

If the momentum of an electron is $1.95 \times 10 ^ { - 27 } \mathrm {~kg} \cdot \mathrm { m } / \mathrm { s }$ , what is its de Broglie wavelength? $( h =$ $6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s }$ )

A) $420 \mathrm {~nm}$
B) $170 \mathrm {~nm}$
C) $340 \mathrm {~nm}$
D) $210 \mathrm {~nm}$
E) $520 \mathrm {~nm}$