Based on their definitions, electron affinity could be considered the opposite of

Explanation:

Ionization energy is the energy released when an electron from the outermost shell of an atom is given out. The opposite is the energy required to put an electron in the outer most orbit of an atom. This energy is termed as electron affinity.

The electron affinity (Eea) of an atom or molecule is defined as the amount of energy released when an electron is attached to a neutral atom or molecule in the gaseous state to form a negative ion. ... In other words, the enthalpy change and the electron affinity differ by a negative sign.

This is the amount of energy needed to pull an electron away from the atom in the gaseous state, or the tendency of an atom to give up electrons. This is conceptually the opposite of electron affinity.

the answer is definitely c.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.