How could you manipulate the number of trials and the sample size to produce valid experimental results

Using the periodic table, complete the table to describe each atom. type in your answers

What produces wave a)sound b) heats c)transfer of energy d)vibrations

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?