In the chemical reaction, mg + 2hcl mgcl2 + h2 how many moles of hcl are needed to completely react with 3.5 moles of mg? a. 3.0 b. 2.0 c. 7.0 d. 3.5 reset submit

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole

What type of energy do chemical bonds have? what type of energy is it converted to during chemical reactions? question 15 options: chemical bonds have kinetic energy, which is converted to potential energy during chemical reactions. chemical bonds have electric energy, which is converted to potential energy during chemical reactions. chemical bonds have heat energy, which is converted to kinetic energy during chemical reactions. chemical bonds have potential energy, which is converted to heat energy during chemical reactions.

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.