Why is human skin purple when UV light is shined on it?

C2 H4 + 3O2 = 2CO2 + 2H2O How many moles of methane will be burnt to produce 0.1 of water

In which scenario is a chemical change occurring? A. A cup of ice cream is melting. B. A block of dry ice is sublimating. C. A section of iron fence is corroding. D. A flask of chlorine gas is condensing.

An atom containing 7 protons, 8 neutrons, and 7 electrons: An atom containing 7 protons, 8 neutrons, and 7 electrons: cannot exist. is an ion. is charge-neutral. is an oxygen atom. none of the above

You need to prepare at 2.0 mL sample of a diluted drug for injection. The total amount of the drug to be injected in this 2.0 mL injection is 0.0210 mg of drug/kg-body mass. Assume the average body mass of 70 kg.

Which statement about temperature, humidity, and pressure in an air mass is true? A. The temperature is the same throughout but the humidity and pressure vary widely. B.

Which is the best definition of activation energy? O the energy required to end a chemical reaction O the energy required to bind a substrate to an active site O the energy required to form or break the bonds of reactant molecules O the energy

A chemist wants a 0.100 m solution of naoh. She has 0.0550 mol naoh available. What volume of solution is needed to make the mixture?

Which of the following is the most important factor when determining a safe speed? A) Number of passengers on your boat B) Distance from the nearest safe shoreline C) Presence of a safe water buoy D) Wind, water conditions and currents

Which of the following statements about water is true? It's strongest intermolecular forces are London dispersion forces It's a non-polar molecule It's a solid at room temperature and pressure It's a solid form is less dense than the liquid form

At 25.0 degrees Celsius, one milliliter of mercury has a mass of 13.6g. How many liters of mercury are required to have a mass of 500 Kg of mercury?