C₂H₃O₂⁻ is an anion.
<u>Explanation:</u>
NaC₂H₃O₂(s) → Na⁺(aq) + C₂H₃O₂⁻(aq)
NaC₂H₃O₂ when dissociated, yields Na⁺ and C₂H₃O₂⁻.
Anion is a negatively charged ion.
In this case, C₂H₃O₂⁻ is an anion.
The flow of Direct current (DC) is constant and flows in one direction. Most digital electronics make use of DC. Alternating current (AC) periodically flows in reverse and is mostly used to deliver power to houses, buildings and the like. With that alone, you can already rule out A, C and D.
The answer would then be B. constant, periodically reversing.
Subatomic particles
Explanation:
Grand unification theory or GUT is a model that tries to describe the universe.
Answer:
The photon has a wavelength of 
Explanation:
The speed of a wave can be defined as:
(1)
Where v is the speed, 
is the frequency and 
is the wavelength.
Equation 1 can be expressed in the following way for the case of an electromagnetic wave:
(2)
Where c is the speed of light.
Therefore, 
can be isolated from equation 2 to get the wavelength of the photon.
(3)
Hence, the photon has a wavelength of
<em>Summary: </em>
Photons are the particles that constitutes light.
