Electrons in an atom are arranged in layers, or shells. For example, an atom of titanium has two electrons in its innermost electron shell. The next two layers contain eight and ten electrons, and the outermost layer contains two electrons. What does the number of electrons in the outermost shell of an element indicate?
A.
How many protons and neutrons are in an atom
B.
Whether an element is likely to bond with other elements
C.
What state of matter an element is usually found in
D.
Whether an element is radioactive