Answer:

Explanation:
We need to use the formula for heat of vaporization.

Identify the variables.
- The heat absorbed by the evaporating water is the <u>latent heat of vaporization. </u>For water, that is 2260 Joules per gram.
- Q is the energy, in this problem, 50,000 Joules.
- m is the mass, which is unknown.

Substitute the values into the formula.

We want to find the mass. We must isolate the variable, m.
m is being multiplied by 2260 J/g. The inverse operation of multiplication is division. Divide both sides by 2260 J/g.


Divide. Note that the Joules (J) will cancel each other out.


Round to the nearest whole number. The 1 in the tenth place tells us to leave the number as is.

The mass is about 22 grams, so choice B is correct.
Answer:
photons
Explanation:
Where,
n is the number of photons
h is Plank's constant having value
c is the speed of light having value
is the wavelength of the light
Given that, wavelength = 514 nm = 
Energy = 10.0 mJ = 0.01 J ( 1 mJ = 0.001 J )
Applying the values as:-

photons
A. Water can dissolve a wide variety of substances
Answer:
The size of an isolated atom can't be measured because we can't determine the location of the electrons that surround the nucleus. We can estimate the size of an atom, however, by assuming that the radius of an atom is half the distance between adjacent atoms in a solid. This technique is best suited to elements that are metals, which form solids composed of extended planes of atoms of that element. The results of these measurements are therefore often known as metallic radii.
.Explanation: