Sig figs. What is the result of ?  Answer in mol. Do not use scientific notation. Do not write units.

chapter 6. A -2 ion has the valence electron configuration 5s24d5. What is the element?

Chapter 5. The heat capacity of gallium is 0.37 J/(g*K). The heat capacity of water is 4.18 J/(g*K). A 75.4 g sample of gallium is cooled to 251 K. It is dropped into 50.0 g H2O at 295 K. What is the final temperature? Answer in K. Do not type units. Do not use scientific notation.

Chapter 2. Match the material with the best description of it. Each descriptor can be used only once. The descriptors are: element, ion, polyatomic ion, and isotope. carbon-12 and carbon-13 are examples of [one] perchlorate is an example of [two] F2 is an example of [three] chromium (V) is an example of [four]    

Use the distributive property to FACTOR

Solve 52-17 using the manipulative blocks below.

Explain how the model below can be used to illustrate that 7 = 18-11.

Simplify the following.  Leave the answer as a power.

In new math textbooks, there is an emphasis on mental mathematics and estimation.  Explain why this might be important for today’s students.  

Subtract using a number line. 10 – 3