A: It prevents most reactions from occurring spontaneously.
The answer above is correct.
Physical<span> changes involve a new </span>form<span> or shape of matter,
</span>
Chemical change<span> is any </span>change<span> that results in the formation of new </span>chemical<span> substances.</span>
Answer:
The mean free path = 2.16*10^-6 m
Explanation:
<u>Given:</u>
Pressure of gas P = 100 kPa
Temperature T = 300 K
collision cross section, σ = 2.0*10^-20 m2
Boltzmann constant, k = 1.38*10^-23 J/K
<u>To determine:</u>
The mean free path, λ
<u>Calculation:</u>
The mean free path is related to the collision cross section by the following equation:

where n = number density

Substituting for P, k and T in equation (2) gives:

Next, substituting for n and σ in equation (1) gives:

The correct answer is option 2. When Pt2+ is reduced it loses electrons, oxidizing it. The oxidation number is the charge of the atom. Adding an electron, decreases the net charge consequently the oxidation number.
Calcium is a really soft type of metal.
~Deceptiøn