What part of an atom cannot change without changing the atom's identity?

What is the final pressure (expressed in atm) of a 3.05 l system initially at 724 mm hg and 298 k, that is compressed to a final volume of 2.60 l at 273 k?

A newly discovered element, Y, has two naturally occurring isotopes. 87.8 percent of the sample is an isotope with a mass of 267.8 u, and 12.2 percent of the sample is an isotope with a mass of 269.9 u.

The equilibrium constant for the reaction of fluorine gas with bromine gas at 300 K is 54.7 and the reaction is: Br2 (g) + F2 (g) ⇔ 2 BrF (g) What is the equilibrium concentration of fluorine if the initial concentrations of bromine and fluorine

Which two gases can not be broken down by chemical means? CO and He CO and NH3 Xe and He Xe and NH3

Give the number of significant figure in this number 2.115

As transformações estão presente em nosso cotidiano, elas nunca param de acontecer, na sua maioria invisível a olho nu. Quais critérios é preciso observar para identificar se ocorreu transformação?

U human ear is measured in?

Is the earth older than any of the rock layers.

Problem page liquid hexane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water. what is the theoretical yield of water formed from the reaction of of hexane and of oxygen gas?

Calculate the mass percent of a NaCl solution in which 140g of NaCl is dissolved in 4.50L of water at 25C (density = 0.997g/mL).