What does the subscript 2 indicate in the compound mgcl2?

You have a sample of a gas that occupies a volume of 17ml at -111 degrees celsius. what volume does the sample occupy at 88 degrees celsius? show all work asap

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

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