How many kilograms does a 1.60 ton elaphant weigh

1451.496

Explanation:

A unit of weight equal to 1,000 kilograms, or approximately 2,204.6 pounds

tons =

kg

1000.0

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.