C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
Answer:
Heterogeneous mixture
Explanation:
A homogeneous mixture is defined as a mixture in which the constituents of the mixture are uniformly distributed. A typical example of a homogeneous mixture is when a salt is dissolved in water.
A heterogeneous mixture refers to a kind of mixture whereby the composition of the mixture is not uniform. A typically example of a heterogeneous mixture is non-homogenized milk.
Since non-homogenized milk is not homogeneous, the cream rises to the top and separates from the rest of the mixture because the emulsion has not been stabilized. However, homogenized milk is just milk whose emulsion has been stabilized the cream does not separate when left to stand.
Answer:

Explanation:
Hello,
The frequency and wavelength of electromagnetic waves propagating in free space might be related to each other by using the following equation:
c=λf
Solving for the frequency:
f=c/λ
Knowing that λ stands for the wavelength (642 nm for the mentioned incident light), c the light velocity (300.000 m/s) and f the frequency, we get the asked frequency as:
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a small cavity or space in tissue, especially in nervous tissue as the result of disease.