What is the energy efficiency of a light bulb that gives you 30 units of usable energy for every 100 units of energy put in to it?
a. 0.3
b. 3
c. 30

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

Why do cells appear different in distilled water than they do in 10% salt water?

Which of the following is a conclusion that resulted from ernest rutherford’s scattering experiment? (will mark brainliest) a. the nucleus is negatively charged b. the atom is a dense solid and is indivisible c. the mass is conserved when atoms react chemically d. the nucleus is very small and the atom is mostly empty space