An aircraft travels 100.km west and then travels 500. km west. What is its total displacement?

How many atoms of oxygen are contained in 160 grams of n2o3

100mg magnesium reacts with 20ml of 1.0m hcl

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.