Atom A emits mainly X rays when it is excited. Atom B emits mainly gamma rays. Which emission corresponds to a transition between energy levels that are closer in energy? Explain your answer. (Hint: Refer to the electromagnetic spectrum)

Explain how are elements classified and provide an example

Assume that you measured exactly 2.0 mL of the sodium chloride solution into a small test tube. How many moles of sodium chloride are in the tube?

4. Another term for a pre-inspection agreement is A. pre-sale inspection. B. partial inspection. C. scope of work. D. standard of practice.

4. Write a chemical formula for a compound that has two atoms of oxygen (0) and three atoms of iron (Fe).

Name one property that all metalloids have in common.

A container has a volume of 200 L at 0.94 atm and 25 C. The pressure changes to 1.00 atm and the temperature changes to 0 C. What is the new volume of the container

f litmus paper is dipped in an acidic solution and then in a basic one, what will happen? The paper will turn from blue to red. The paper will turn from red to clear. The paper will turn from blue to clear. The solution will turn from red to blue.

You need to make an aqueous solution of 0.125 M barium chloride for an experiment in lab, using a 250 mL volumetric flask. How much solid barium chloride should you add?

Relative to the sum of the masses of its constituent nucleons, the mass of a nucleus is: greater the same smaller sometimes greater and sometimes smaller

Smallpox epidemic among Native Americans?