here is an attached photo with a detailed explanation, good luck!
Question in incomplete, complete question is:
Technetium (Tc; Z = 43) is a synthetic element used as a radioactive tracer in medical studies. A Tc atom emits a beta particle (electron) with a kinetic energy (Ek) of
. What is the de Broglie wavelength of this electron (Ek = ½mv²)?
Answer:
is the de Broglie wavelength of this electron.
Explanation:
To calculate the wavelength of a particle, we use the equation given by De-Broglie's wavelength, which is:

where,
= De-Broglie's wavelength = ?
h = Planck's constant = 
m = mass of beta particle = 
= kinetic energy of the particle = 
Putting values in above equation, we get:


is the de Broglie wavelength of this electron.
The softest mineral in the Mohs Hardness Scale is talc.
Talc is often used in baby powder and corn starch, among other things. Talc cleaves into thin sheets, and it is held together only by van de Waals bonds, which allows these sheets to slip past each other. This gives the mineral its softness and it is often valued as a high-temperature lubricant.