What happens when zinc carbonate is calcined?

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

In a ball-and-stick molecular model, what do the sticks represent?