Ethane burns according to the following reaction: C3H8 + 5O2 → 3CO2 + 4H2O + 2.04 x 103 kJ How much heat is produced when 150 grams of oxygen gas are consumed?

Asample of silver (with work function ? = 4.52 ev) is exposed to an ultraviolet light source (? = 200 nm), which results in the ejection of photoelectrons. what changes will be observed if: silver is replaced with copper (? = 5.10 ev) more photoelectrons ejected no photoelectrons are emitted fewer photoelectrons ejected more energetic photoelectrons (on average) less energetic photoelectrons (on average)

Who is better, messi or cristiano, i need this for a chemistry class. asap

Acamcorder has a power rating of 17 watts. if the output voltage from its battery is 7 volts, what current does it use?units: