Why is studying animals in the wild considered to be somewhat experimentally out of control

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver

Light waves are as they pass through the