Question

which of these is a light element? (1 point)

iron

oxygen

carbon

lithium

Explanation:

Light elements are defined as elements with an atomic number of 20 or less, and among the options, iron has an atomic number of 26, while oxygen (8), carbon (6), and helium (2) have atomic numbers ≤20. However, helium is a noble gas and is one of the lightest elements, and in the context of common classifications, helium is a light element, while iron is a heavy element.

Answer:

D. Helium