Which sample is a pure substance?

According to observations, the overall chemical composition of our solar system and other similar star systems is approximately (a) 98% hydrogen and helium, 2% all other elements combined; (b) 98% ice, 2% metal and rock; (c) 100% hydrogen and helium.

What kind of element has the greatest tendency to attract electrons? why?

The first four ionization energies for an imaginary element, Xz, are E1 = 102 kcal, E2 = 186 kcal, E3 = 4021 kcal, and E4 = 4862 kcal. The most probable number of valence electrons as indicated by this ionization data is:

Select the correct answer. What statement is true about the presence of cl - in solution? A. It will cause an increase in the pH. B. It will cause a decrease in the pH. с. It will not affect the pH. D It will cause an increase in OH ions.

A block of wood has a mass of 120g and a volume of 200cm what is the density

Which type of experiment follows ethical standards?

What kind of change occurs when a compound is separated into its components?

The reaction rate low is independent of which of the following charactetics • Reactor type] • Temperature • Concentration of components • Pressure

Given that the equilibrium constant for a reaction is 0.00010, what does this tell us about the position of equilibrium for that reaction?

1. Ionic compounds generally form solids because: