True or false uranium-238's stable form is lead

Match each object to its description: a. coma of a comet b. comet tail c. oort cloud haze surrounding a nucleus created by solar wind. hypothetical sphere around the solar system

Compare and contrast physical changes with chemical changes.

A4.86 g piece of metal was placed in a graduated cylinder containing 15.5 ml of water. the water level rose to 17.3 ml. what is the density of the metal. i need the steps of how to solve it to so i can use a formula to work out other problems.