Answer:
C
Explanation:
thats my guess but im not completely sure
Hello,
Here is your answer:
The proper answer to this question is option D "wood is burned". Its a chemical change because its changing forms wood to ash.
Your answer is D.
If you need anymore help feel free to ask me!
Hope this helps!
Answer:
16%
Explanation:
Crotonic acid : C₃H₅CO₂H
C₃H₅CO₂H ⇄ C₃H₅CO₂⁻ + H⁺
C O O
where : C = C ( 1 - ∝ ) , O = C∝
also: Ka = C∝² / ( 1 - ∝ ) ---- ( 1 )
<em>From Alexa data resource : </em>
Pka = 4.69 , [ Ka = 2.04 * 10^-5 = C∝² / ( 1 - ∝ ) ]
back to equation 1
2.04 * 10^-5 = [ ( 0.63 * 10^-3 ) * ∝² / ( 1 - ∝ ) ] ----- ( 2 )
∴ ∝² / ( 1 - ∝ ) = 3.24 * 10⁻²
Resolving equation above
∝ = 0.1645 = 16.45%
Answer:
The answer to this question is given below in the explanation section.
Explanation:
The Bohr model depicts an atom as a small, positively charged nucleus surrounded by electrons.These electrons travel in circular orbit around the nucleus similar in structure to the solar system,except electrostatic forces rather than gravity provide attraction.Electron orbit around the nucleus resembles that of planets around the sun in the solar system.
The Bohr model was an improvement on the earlier cubic model(1902),the plum pudding model(1904) the saturnine model (1904) the rutherford model (1911) since the Bohr model is a quantum physics based modification of the Rutherford may source combine the two:the Rutherford-Bohr model
Although revolutionary at the time,the Bohr model is a relatively primitive model of the hydrogen atom compared to the valence shell atom.As an initial hypothesis it was derived as a first order approximation to describe the hydrogen atom.Due to its simplicity and correct results for selected systems.
In 913 Bohr suggested that electrons could only have certain classical motions:
- Electrons in atoms orbit the nucleus.
- The electrons can only orbit stably,without radiating in certain orbits at a certain discrete set of distances from the nucleus.These orbit are associated with definite energies and are also called energy shells or energy levels.
- Electrons can only gives or lose energy by jumping from one allowed orbit to another,absorbing or emitting electromagnetic radiation with a frequency (v) determined by the energy difference of the levels according to the plank relation.
The concentration of the drug stock solution is 1.5*10^-9 M i.e. 1.5 * 10^-9 moles of the drug per Liter of the solution
Therefore, the number of moles present in 1 ml i.e. 1*10^-3 L of the solution would be = 1 *10^-3 L * 1.5 * 10^-9 moles/1 L = 1.5 * 10^-12 moles
1 mole of the drug will contain 6.023*10^23 drug molecules
Therefore, 1.5*10^-12 moles of the drug will correspond to :
1.5 * 10^-12 moles * 6.023*10^23 molecules/1 mole = 9.035 * 10^11 molecules
The number of cancer cells = 2.0 * 10^5
Hence the ratio = drug molecules/cancer cells
= 9.035 *10^11/2.0 *10^5
= 4.5 * 10^6
