The group notices that horizontally from left to right—the atomic mass increases; solids on the left and colorless gases on the right; combining power increases from 1 to 4 and then goes back down to 1 (or 0).
The group considers possible patterns that occur vertically: density, combining power, metals/metalloids/non-metals (but then they decide that's a horizontal pattern); melting point (they decide that doesn't work); and reactions with other materials.
After several minutes of discussion (not on the video clip), the group summarizes their thinking: for metals on the left of the table the reactivity increases as you go down the columns; for non-metals on the right the reactivity increases as you go up the columns.
The group goes through each of the possible properties in CQ 6-1 and decides whether the unknown element might have those properties. They eventually decide on choice C.
Group discusses CQ 6-2. They quickly decide it cannot be choices B or C. Then they try to figure out whether it is A or D and have a long discussion about what property to consider. [Only a small part of that discussion is included on the video clip.] Finally they decide that choice D makes more sense.
UCR L6 Video Clip 1: Group discusses patterns occurring horizontally
UCR L6 Video Clip 1: Group discusses patterns occurring horizontally