When a nuclide's nucleus contains more protons than neutrons, a positron is created, whereas radionuclides are utilized to emit both a positron and a neutrino.
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What exactly does positron emission tomography entail?</h3>
In the field of medical diagnostics, it is simple to monitor the positron emission of radiotracers. Positron-emission tomography, also known as PET scans, is frequently used to examine the structure and function of the brain. When an isotope annihilates an electron, positrons are released, which are used in positron-emission tomography. As a result, alpha photons are released that are 180 degrees apart from one another. The devices can now identify these protons, and they can also evaluate photos. A positron emission tomography (PET) scan is an imaging procedure that can help show how your tissues and organs' metabolisms or biochemical processes work. In order to display both typical and abnormal metabolic activity, the PET scan uses a radioactive substance (tracer).
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Diffusion is the movement of a solute from an area of its high concentration to an area of its low concentration – i.e. down a concentration gradient. This process is “passive” – i.e. it requires no energy; the gradient is enough to drive the process.
Answer:
pA = 0.095 atm
pB = 0.303 atm
Explanation:
Step 1: the reaction
AB(s) ⇔ A(g) + B(g)
Kp = pA * pB
⇒ with Kp = equilibrium constant
Kp = 0.126 * 0.23 ⇒ Kp = 0.02898
Since the container will be compressed to half of its original volume, means that he pressure will be doubled.
⇒pA = 0.252
⇒pB =0.46
To establish this equilibrium, each pressure has to be lowered by x
⇒pA = 0.252 - x
⇒pB = 0.46 - x
Kp = 0.02898 = (0.252 - x)(0.46-x)
0.02898 = 0.11592 - 0.252x -0.46x + x²
-x² + 0.712x - 0.08694 = 0
D= b² - 4ac
⇒ D = 0.712² -4*(-1) *(-0.08694) = 0.506944 -0.34776 =0.159184
x = (-b ± √D)/2a
x = (-0.712 ± √0.159184)/(2*-1) = (-0.712 ± 0.398978696)/-2
x = 0.156510652 or x= 0.555489348
x = 0.555489348 is impossble or the pressure would be negative
x=0.156510652
pA =0.252 - 0.156510652 = 0.095489348 atm
pB = 0.46 - 0.156510652 = 0.303489348 atm
In metallic bonding, valence electrons of metals move freely between neighbouring atoms. metals are ductile
because the forces that hold their atoms together are weak.
Explanation:
- Metallic bonds are the force which holds atoms together in a metal.
- Valence electrons present in the metals are freely moving between the other neighbouring atoms. The interaction between the positive ions which electrons leave behind and the valence electrons give the binding force which able to hold the metallic crystal together as it is.
- In metals, the electrons are free to travel from one metal to another metal. This speciality is the reason for their electric conductivity. And this shows that the metal-metal bond is weak in metal.
