14. how is the number of neutrons in the nucleus of an atom calculated?
add the number of electrons and protons together.
subtract the number of electrons from the number of protons.
subtract the number of protons from the mass number.
add the mass number to the number of electrons.

Calculate the change in entropy if br2(l) is converted into gaseous br atoms. s° for br2(l) = 152.2 j/(mol•k) s° for br2(g) = 245.5 j/(mol•k) s° for br(g) = 175.0 j/(mol•k)

Problem #3 (ch. 1, problem 15)the ideal gas law provides one way to estimate the pressure exerted by a gas on a container. the law isí‘ťí‘ť=푛푛푛푛푛푛푉푉mo re accurate estimates can be made with the van der waals equationí‘ťí‘ť=í‘›í‘›í‘›í‘›í‘›í‘›í‘ ‰í‘‰â’푛푛푟푟â’푞푞푛푛2í‘ ‰í‘‰2where the term nb is a correction for the volume of the molecules and the term an2/v2is a correction for molecular attractions. the values of a and b depend on the type of gas. the gas constant is r, the absolutetemperature is t, the gas volume is v, and the number of moles of gas molecules is indicated by n. if n = 1 mol of an ideal gas were confined to a volume of v = 22.41 l at a temperature of 0â°c (273.2k), it would exert a pressure of 1 atm. in these units, r = 0.0826.for chlorine gas (cl2), a = 6.49 and b = 0.0562. compare the pressure estimates given by the ideal gas law and the van der waals equation for 1 mol of cl2 in 22.41 l at 273.2 k. what is the main cause of the difference in the two pressure estimates, the molecular volume or the molecular attractions?

In this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced?