Which is not a common characteristic of transition metals? A. plentiful in the human body

B. hard and shiny

C. form colorful compounds

D. good electrical conductors

What element breaks down into yttrium-90?

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?

Choose all the answers that apply. fluorine (f) has an atomic number of 9 and an atomic weight of 18.99. fluorine has a. 9 protons b. 10 neutrons c. 18 electrons d. an atomic mass of 19 e. at least one isotope