Nearly 150 years ago, man-made CO2 was introduced into the atmosphere primarily through . Currently, is the main contributing factor to increased levels of human-produced CO2 in the atmosphere.

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.

One student said that the investigation was not valid (a fair test). write a plan for the investigation that includes improvements to the method and apparatus

Of element x has 22 protons, how many electrons does it have