The number of chorus students increase by a factor of 1.2 from the previous year. write 1.2 as a percent

Since the percent sign has 2 zeros:% then that means to convert a decimal to a percent,move the decimals to the right 2 spaces.Now,1.2 should look like this:120. You add the zero because that space is worth nothing,but it is used for the spaces.

1.2 as a percent is 120%, so the students in chorus increased by 120%.

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table