Question

Including: # of particles, temperature, average kinetic energy, molar mass, average velocity, electronegativity and atom size, which of these are the same or different for all of the elements?

A box contains equal amounts of helium, argon, and krypton (all gases) at 25 ∘C. Consider the temperatures, masses, average velocities, and average kinetic energy of the three kinds of gas in the mixture.

Answer 1

Number of particles, temperature, kinetic energy, average velocity will be the SAME. Molar mass, electronegativity and atom size will be DIFFERENT.

Explanation:

Your statement tells us that you have equal amounts of each gas (Helium, Argon and Krypton) this means you will have the same number of particles of each.

We are also told that all gases are in the box at the same temperature - therefore they have the same temperature.

The Kinetic energy of a particle is connected with it's velocity (i.e. more kinetic energy results in a fast velocity) and energy is related to the temperature (and pressure) of a system. As we have now stated all gases are at the same temperature, they can be considered as having the same kinetic energy and thus the same velocities.

Each element has a different relative atomic mass (ignoring potential isotopes) as they each have a different number of protons and neutrons. Therefore they each have a different molar mass.

The electronegativity of an element is as a result of it's electron configuration and structure. As we have already established all elements have a different number of protons and neutrons, they also posses different numbers of electrons and thus have a different electron configuration and structure. This will result in different electronegativities between the elements.

An atoms size is also related to the number of protons, neutrons and electrons within an atom. As all elements will have different numbers of these particles, they will also have different sizes. All gases given are different elements and so will have different sizes.