the half life of potassium-40 (K-40) is 1.35 billion years. If you begin with 130 g of K-40, how much remains after 2.5 billion years? use the correct number of significant digits in your answer

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.

The diagrams to the right show the distribution and arrangement of gas particles in two different containers. according to kinetic-molecular theory, which of the following statements is true? check all that apply. if the temperatures of both containers are equal, container a has greater pressure than container b. if the volume of container a decreased, its pressure would decrease. if the pressure in both containers is equal, container a has a lower temperature than container b.

8) warming your hands by a fire is an example if which heat transfer? a. conduction b. convection c. radiation d. none of these