Why aren't things that you can buy at the store like vinegar (Acetic acid), rubbing alcohol (Isopropyl alcohol), Hydrogen peroxide or Gasoline pure substances. Explain.

The speed of light is around 6.706×10^8 miles per hour. what is the speed of light in units of miles per minute?

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks.energy was destroyed inside the blocks.energy was absorbed into the blocks from outside the system.energy was transferred from the warmer block to the cooler block.

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit