A piece of cloth was painted with organic dye 28,650 years ago. What percentage of the original carbon-14 in the organic dye remains after all this time

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 ?

One similarity and one difference between an element and a mixture of elements

What happens in the particles of a gas when the gas is compressed