Which of the following elements has properties different than the rest?
K
O
H
N

The ammonia molecule in the diagram has the observed bond orientation because

Which is an example of a highly unstable isotope that is often used in fission reactions?

Awhite powder is added to a solution. the images show observations made before the powder is added, just after the powder has been added, and a little while later. (the liquid in the small beaker is phenol red solution.) what evidence shows that a chemical change has taken place?