Maria on the moon are not seas as once thought, but fields of (blank) from volcanoes that are no longer active. What is blank??

What is the smallest component or the most basic building block of any element ? a. an atom, b. a compound c. gas d. element

What is the maximum number of electrons that an atomic orbital can contain?

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space