If i have three compounds, c12h22o11, ch3cooh, ch3oh, what does this tell me about the makeup of any compound if they’re made up of the same three elements in different ways?

As you move from right to left on the periodic table the atomic radius fill in the blank

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

What is a number added in front of a formula in order to balance the equation