Which is evidence that the reaction below is a redox reaction?
2na + cl2 _ 2nacl

the sodium atom is a pure element as a reactant and becomes part of a compound.
two different elements take part in the reaction.
oxidation occurs to both elements in the reaction.
there are no ions in the equation.

The correct answer is:

Two different elements take part in the reaction.

Explanation:

A redox reaction is generally defined as chemical reaction in which oxidation and reduction takes place simultaneously.It is a reaction between two species among which gain and loss of electrons takes place.

So, in the given reaction, sodium metal looses an electron to chlorine atom to form sodium chloride molecule.

Oxidation

Reduction

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.