Which of the following is a producer?
a. a crow that consumes a dead animal on the side of a road
b. a fish that eats smaller fish for its food
c. a giraffe that eats the leaves of trees
d. a plant that has insect larvae feeding on its roots

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.

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.