So here in this example question it says which of the following elements has physical properties most similar to barium O. We have carbon which is represented by the symbol C, Calcium which is CA, Arsenic which is as Xenon which is Xe and chlorine which is CL. Now in order to understand which one has physical properties similar to barium, we have to know what the classification of barium is. Is barium of metal a nonmetal or a metalloid?

So if we go up here, we've highlighted the element barium in black and then the other five choices in blue. We can see here that barium is shaded red. So barium represents a metal. Therefore we're looking for another element that is a metal because then they would share similar physical properties such as opaqueness, opaqueness, malleability, conductivity, etcetera.

Now, calcium looks like the only other one that's red, right? Calcium is our metal. Arsenic is a metalloid because it's green. Carbon, chlorine and xenon are nonmetals because they're shaded blue. So coming back down to our question, we see that calcium is our answer. So be with be would be the correct choice.

So just remember when they're giving you an element and asking you to determine which one has similar physical properties, look for the classification of the element. Is it a metal, a nonmetal or metalloid? Use that to guide you to the right answer.