Copper is made of two isotopes. copper-63 is 69.17% abundant and it has a mass of 62.9296 amu. copper-65 is 30.83% abundant and it has a mass of 64.9278 amu. what is the weighted average of these two isotopes?

Which type of bond is present in hydrogen sulfide (h2s)? the table of electronegativities is given. a. hydrogen b. ionic c. nonpolar covalent d. polar covalent

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.

Some molecular compounds, such as hcl, ionize completely in solution. for molecular compounds such as h2co3, most molecules do not ionize in solution. which describes the properties of these two solutes? a. hcl and h2co3 have the same effect on the properties of the solution. b. hcl raises the freezing point of water more than h2co3 does. c. hcl raises the boiling point of water more than h2co3 does.