A 390 mL solutions of 4.6 M HCl is left out over the weekend and 74 mL of solvent evaporates. What is the new concentration of HCl?

What does x represent in the formula for the compound xcl4?

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

One similarity and one difference between an element and a mixture of elements