8. How many joules are needed to change 42.3 g of lead from 44.3°C to 76.8°C? The specific heat of lead is 0.130 J/g °C.

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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)

How much heat is added if 0.814g of water increase in temperature by 0.351 degree c?

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2