Explanation:
speed of light= c
wave length= L
frequency= f
c=Lf → L= c/f → L= 3 × 10⁸/ 27 × 10⁹ → L = 1/90 ≈ 0.011 m
The answer is mass. I have to comment more than 20 characters.
Answer:

Explanation:
<u>Charge of an Electron</u>
Since Robert Millikan determined the charge of a single electron is

Every possible charged particle must have a charge that is an exact multiple of that elemental charge. For example, if a particle has 5 electrons in excess, thus its charge is 
Let's test the possible charges listed in the question:
. We have just found it's a possible charge of a particle
. Since 3.2 is an exact multiple of 1.6, this is also a possible charge of the oil droplets
this is not a possible charge for an oil droplet since it's smaller than the charge of the electron, the smallest unit of charge
cannot be a possible charge for an oil droplet because they are not exact multiples of 1.6
Finally, the charge
is four times the charge of the electron, so it is a possible value for the charge of an oil droplet
Summarizing, the following are the possible values for the charge of an oil droplet:

Answer:
88.2 C
Explanation:
The current can be defined as the rate of flow of charge in a conductor.
The relation between charge current and time is given as
I = Q/T
I = current, Q= charge and T = time
that is ampere = coulomb / second
The amount of charge passed is from the negative to the positive terminal
shall be given by:
Q = I * t = 3.5mA * 7h * 3600s/h = 88.2 C
Note: take care of the units.
The amount of heat required is B) 150 J
Explanation:
The amount of heat energy required to increase the temperature of a substance is given by the equation:

where:
m is the mass of the substance
C is the specific heat capacity of the substance
is the change in temperature of the substance
For the sample of copper in this problem, we have:
m = 25 g (mass)
C = 0.39 J/gºC (specific heat capacity of copper)
(change in temperature)
Substituting, we find:

So, the closest answer is B) 150 J.
Learn more about specific heat capacity:
brainly.com/question/3032746
brainly.com/question/4759369
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