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.
Answer:
50000ppm and 0.855M.
Explanation:
ppm is an unit of chemistry defined as the ratio between mg of solute (NaCl) and Liters of solution. Molarity, M, is the ratio between moles of NaCl and liters
A 5% (w/v) NaCl contains 5g of NaCl in 100mL of solution.
To solve the ppm of this solution we need to find the mg of NaCl and the L of solution:
<em>mg NaCl:</em>
5g * (1000mg / 1g) = 5000mg
<em>L Solution:</em>
100mL * (1L / 1000mL) = 0.100L
ppm:
5000mg / 0.100L = 50000ppm
To find molarity we need to obtain the moles of NaCl in 5g using its molar mass:
5g * (1mol / 58.5g) = 0.0855moles NaCl
Molarity:
0.0855mol NaCl / 0.100L = 0.855M
Answer:
Upwelling is the natural process which brings cold, nutrient-rich water to the surface. A huge upwelling regularly occurs off the coast of Peru, which enjoys a large fishing industry as a result. Upwelling is a process in which currents bring deep, cold water to the surface of the ocean.
Explanation:
good luck
Carbon dioxide has a total of 16 valence electrons. 1. To determine the number of valence electrons of carbon dioxide (CO2), first determine the number of valence electrons of each of the elements in the molecule.
a. We have 1 carbon (C) molecule, and 2 oxygen (O) molecules.
b. The carbon molecule has 4 valence electrons and each oxygen molecule has 6 oxygen molecules.
2. Add up the valence electrons of each of the elements
4 + (2 x 6) = 16
(from C) (2 oxygen molecules, with 6 valence electrons each)
Thus, CO2 has a total of 16 valence electrons.
The number of valence electrons can be more clearly seen from the Lewis structure of the CO2 in the figure below (Source: http://chemistry.tutorvista.com/inorganic-chemistry/bonding-electrons.html). The the dots surrounding the letters represent the valence electrons.
