A metal with a specific heat of 0.780 J/g °C requires 660 J of heat to raise the temperature (the change in temperature) by 25 °C. What is the mass of the metal?

List four observations that indicate that a chemical reaction may be taking place

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have