Express in scientific notation. choose the answer with the proper number of significant figures. a). 20. x 10^26 b). 10 x 10^26 c). 2 x 10^27

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.

Which type of intermolecular attractions holds ammonia molecules together with other ammonia molecules?

Apropane torch is lit inside a hot air balloon during preflight preparations to inflate the balloon. which condition of the gas remains constant