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.
<span>In organic chemistry, covalent bonding is most often associated with carbon compounds, which are known as organic chemicals. Hydrogen is also involved most of the time, as well as oxygen. Other elements can also be involved, but less frequently.</span>
<u>Out of all given option, the following statements are true about a system:</u>
- A system is a group of objects analyzed as one unit.
- Energy that moves across system boundaries is conserved
Answer: Option A and B
<u>Explanation:</u>
A system is "a complicated item whose parts or segments are identified with probably a portion of different segments", it very well may be material or calculated. All systems have piece, structure, and condition, yet just material systems have instruments (or forms), and just some material systems have shape.
As per systems, all articles are systems or segments of another system. For instance, a nuclear core is a physical material system made out of protons and neutrons related by solid atomic association; a cell is a natural material system made out of related organelles by non-covalent synthetic securities and metabolic pathways; and a logical hypothesis is a consistent reasonable system made out of theories, definitions, and hypotheses related by relationship and conclusion.
69. The student's skin was obviously warmer than the initial temperature of the bracelet. According to the second law of thermodynamics, heat transfers from a higher temperature to a lower temperature hence heat transfers from the student's skin to the bracelet warming up the bracelet.
70. moles of copper=mass of copper/molar mass of copper
=30.1g/(63.55g/mol)= 0.4736 moles Cu
71. Delta H( heat released) = mCp(deltaT) = 30.1g(0.385 J/gK)(33-19)K = 162.23J
72. Copper is chemically less active than iron.
B is the answer..!
Disturbance is in a circular motion
