--- An atom of element X contains 15 electrons and 16 neutrons.

(a). (I) State the mass number of X.
(ii) Write the electronic
configuration of X.
(b) (I) Write the formula of a chloride of X. pliz , it's urgent. ​

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)

If i initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 k, and then i raise the pressure to 14 atm and increase the temperature to 300 k, what is the new volume of the gas?

What metric units would you use to measure the thickness of a key