I think the correct answer from the choices listed above is the last option. The family that contains disinfectants is the halogens. This group includes the elements fluorine, chlorine, bromine, iodine, and astatine. Disinfectants are chemical agents that inhibit or kill microorganisms on inanimate objects.
C is the correct answer.a buffer reacts with the added acid or base which can produce H+ or hydroxide ion,or a kind of removing H+ or hydroxide added to solution.remember that buffers don't prevent additional acid or base from reacting,they react with the additional themselves.the A and D are completely wrong.
The question is incomplete. Here is the complete question.
An atom of lead has a radius of 154 pm and the average orbitalspeed of the electron in it is about 1.8x
m/s. Calculate the least possible uncertainty in a measurement of the speed of an electron in an atom of lead. Write your answer as a percentage of the average speed, and round it to significant 2 digits.
Answer: v% = 0.21 m/s
Explanation: To calculate the uncertainty, use <u>Heisenberg's Uncertainty Principle</u>, which states that: ΔpΔx≥
where h is <u>Planck's constant</u> and it is equal to 6.626.
m²kg/s.
Since p (momentum) is p = m.v:
mΔv.Δx ≥
Δv = 
Given that: r = x = 1.54.
m and mass of an electron is m=9.1.
kg
Δv = 
Δv = 0.0376.
As percentage of average speed:
Δv.
.100% = 
.10² = 0.021.10 = 0.21%
The least possible uncertainty in a speed of an electron is 0.21%.
The two dimensions of aluminum foil are given 13.72 cm and 8.63 cm respectively with mass 3.1 g.
The density of aluminum is 
. It is defined as mass per unit volume thus, volume of aluminum can be calculated as follows:
Putting the values.
The volume of cuboid is 
, the length and breadth are given, height can be calculated as follows;
Putting the values,
Or, approximately 9.7\times 10^{-3}cm
Therefore, thickness of aluminum foil is 
