A new statue of the town founder is erected in the park. At the unveiling, the statue is a orange-brown copper. After a year, the statue looks blue-green. Has a physical or chemical change taken place?

What makes the Group 1 elements the most reactive metals? They have 8 valence electrons. They have 7 valence electrons. The have no valence electrons. They have 1 valence electron.

How do you find the average atomic mass?

Are products or reactants of this reaction storing more energy in their chemical bond?

Which of the following statements about physical models is not true? a. Physical models are often three-dimensional representations. b. Physical models are used to represent an object or event. c. Physical models are usually in the form of a graph.

Draw the structure of gly-ala-glu in the ionic form that predominates at ph 7

Which statements accurately describe mass? Check all that apply.

What was the first particle discovered inside an atom

Calcium and sulfur ionic compound or non ionic?

Which of the following would release the most heat upon cooling from 75°C to 50°C?

Chlorine atoms each have 17 protons. How many neutrons does each Cl-37 atom have? A. 17 B. 20 C. 37 D. 54