Answer:
Explanation:
we know that 1 km =1000 m and 1 hour =60 min
therefore
239 km/hr =239*1000m/60 min=3983.3 m/min
Answer:
she can use crystalization method.
Explanation:
She should boil that liquid on flame and then cool it down on mederate temprature and check it out rather the crystals formed or not . if crystals are formed then there will be salts.
And if she want topredict the certain salt then she has to perform certain reactions.
Answer:
Active transport
Explanation:
Sodium-potassium pumps are examples of Active type of cellular transport. Sodium potassium pump exchanges sodium ions from potassium ions through the plasma membrane of animal cells.
Whereas Active transport can be defined as movement of ions and molecules across a cell membrane to the region of higher concentration with the help of enzymes and energy.
Answer:
Explanation:
Given parameters:
pH = 3.50
Unknown:
concentration of [H₃0⁺] = ?
concentration of [OH⁻] = ?
Solution:
In order to find the unknown, we use some simple expressions which best explains the pH scale and the equilibrium systems of aqueous solutions.
pH = -log₁₀[H₃O⁺]
[H₃O⁺] = inverse log₁₀ (-pH) =
= 
[H₃O⁺] = 3.2 x 10⁻⁴moldm⁻³
For the [OH⁻]:
we use : pOH = -log₁₀ [OH⁻]
Recall: pOH + pH = 14
pOH = 14 - pH = 14 - 3.5 = 10.5
Now we plug the value of pOH into pOH = -log₁₀ [OH⁻]
[OH⁻] = 
[OH⁻] =
= 3.2 x 10⁻¹¹moldm⁻³
The solution is acidic as the concentration of H₃0⁺ is more than that of the OH⁻ ions.
Concave is not a type of mechanical wave because it doesn’t need a medium for propagation.