When the reaction equation is:
HF ↔ H+ + F-
and when the Ka expression
= concentration of products/concentration of reactions
so, Ka = [H+][F-]/[HF]
when we assume:
[H+] = [F-] = X
and [HF] = 0.35 - X
So, by substitution:
6.8 x 10^-4 = X^2 / (0.35 - X) by solving for X
∴ X = 0.015 M
∴[H+] = X = 0.015
when PH = -㏒[H+]
∴PH = -㏒0.015
= 1.8
Answer: I am actually studying about Stars, so I got you.
3. As the temperature of a star Increases, it's luminosity increases.
As the temperature of a star decreases, it's luminosity decreases.
4. Hot and Bright. The bigger the star, the hotter it gets is from what I learned.
Answer:
PET works by using a scanning device (a machine with a large hole at its center) to detect photons (subatomic particles) emitted by a radionuclide in the organ or tissue being examined.
Newer technology combines PET and CT into one scanner, known as PET/CT. PET/CT shows particular promise in the diagnosis and treatment of lung cancer, evaluating epilepsy, Alzheimer's disease and coronary artery disease.
Explanation: Most Brainliest Please
Answer:
Atomic radius of sodium = 227 pm
Atomic radius of potassium = 280 pm
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
Consider the example of sodium and potassium.
Sodium is present above the potassium with in same group i.e, group one.
The atomic number of sodium is 11 and potassium 19.
So potassium will have larger atomic radius as compared to sodium.
Atomic radius of sodium = 227 pm
Atomic radius of potassium = 280 pm
The volume of the piece of aluminum is 1.96 mL
Explanation:
Density is the relationship of the mass of a substance and its volume.
In this case, the mass of aluminum is 5.30 g and the density is 2.70 g/mL
The formula to apply is;
D=M/V where D is density in g/mL, M is mass in g and V is volume in mL
2.70=5.30/V
V=5.30/2.70 =1.96 mL
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Density of a substance:brainly.com/question/12605423
Keywords: volume, aluminum,density
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