Add 1-2 ml of a 0.1 M lead (II) nitrate solution to a test tube containing 1-2 ml of a 0.1 M potassium iodide solution. Write the balanced equation with states of
matter and ID types of rxn.

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

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.

Which radioisotope is used to date fossils? a. oxygen-16 b. carbon-14 c. uranium-238 d. carbon-12