What is the atmoic number for potassium?

What type of reaction is represented by the following example? 2co2 (g) + 4h2o (l) + 1452 kj 2ch3oh (l) (g) + 3o2 (g) exothermic endothermic

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.

Answer explain why it is not possible to deduce a complete order of reactivity.