Which of the following provides evidence that a chemical change has taken place?

Explain why it is not possible to draw a skeletal structure for methane.

What general trend do you observe in the electronegativity values of the elements as you go from left to right on the table? Given the definition of electronegativity displayed on the table, explain this trend in electronegativity.

What are covalent compounds composed of? A. a metal and a metal B. a metal and a non metal C. a nonmetal and a nonmetal D. an alkali metal and a nonmetal

How do you prepare diluted acid from concentrated acid?

Is mixing paint a physical change if it is why

Rank the elements from smallest to largest electronegativity negativity (smallest at top) 1. N 2. P 3. As 4. Sb

A bicyclist pedaling up a Hill. What type of energy potential or kinetic?

What improvements have been made in modern farming? Select all that apply. 1. machines can do more work over less time 2. better seeds sprout and grow much more quickly 3. trains can transport food over long distances faster 4.

A piece of solid Zn metal is put into an aqueous solution of SnSO4. Write the net ionic equation for any single-replacement redox reaction that may be predicted.

The interactions that are important in the secondary structure of a protein are: a) disulfide bonds. b) peptide bonds. c) hydrogen bonds. d) hydrophobic interactions. e) salt bridges.