Your friend has to plan an experiment for a science fair. he asked for your . his topic is "the strongest cloth for backpacks." what variables must the experinemt include? what variables must be controlled?

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

Between 2014 and 2016, more than 25,000 children in flint, michigan, drank water that was contaminated with lead from lead pipes. during this time, the city claimed the water was safe to drink. which of these actions could the city have taken to ensure that the drinking water was free from lead?

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?