Sonia observed that the two balloons repelled each other. This is because both balloons acquired the same charge when she rubbed them with the piece of wool, and like charges repel each other.
Metals generally form cations, meaning they become positively charge - this positive charge is due to the loss of electrons.
Answer:
Use pOH = -log₁₀ [OH-]
Explanation:
pOH can be calculated from the concentration of hydroxide ions using the formular below:
pOH = -log₁₀ [OH-]
The pOH is the negative logarithm of the hydroxide ion concentration.
Answer : The amount of formaldehyde permissible are, 
Explanation : Given,
Density of air =

First we have to calculate the mass of air.



Now we have to calculate the amount of formaldehyde.
Permissible exposure level of formaldehyde = 0.75 ppm = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Thus, the amount of formaldehyde permissible are, 
Answer:
The answer will be C. Variable
Explanation:
The answer will be C because A response is a reactant for the plant and the question is asking about the light. B is incorrect because stimulus is how a plant reacts to nature for example gravitrophism and thingatropism also its asking about the light not the plant. D is incorrect because... come on now does it even make sense XD
Hope this helps