What does it mean to say mass is conserved during a physical change?

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

Complete the following statements to describe solids, liquids, and gases. select the correct answer from each drop-down menu. a solid a definite volume and a definite shape. a liquid a definite volume and a definite shape. a gas a definite volume and a definite shape