How much heat energy is required to melt 337.1 g of hbr? the molar heat of fusion of hbr is 2.41 kj/mol.

What is the approximate mass of 25 cm3 of silver, if the density is 10.5 g/cm3? a. 0.42 g b. 2.4 g c. 42 g d. 260 g

He nucleus contains the cells genetic material in the form of dna. dna is organized into our chromosomes, which are made up of thousands of that determine our traits.

Sandy is building a small toy car. he wants to use a balloon to power the toy car. he fills a balloon with air and then attaches a straw to the balloon. he tapes the balloon-straw combination to the car and then releases the end of the balloon. the toy moves forward as the air from the balloon comes out the back of the straw. what can sandy do to make the toy car move faster? a) use less air in the balloon. b) blow up the balloon more. c) use a longer straw. d) use larger tires.