How many valence electrons does helium need to have a filled outermost energy level?

When the heat source is removed from a liquid, convection currents in the fluid will

Name three populations found in a prairie ecosystem

What natural and human made features can a map show? Give two examples of each.

Sodium an alkali metal and chlorine a halogen are both in period 3? of the periodic table. Which element has a higher ionization energy? Explain

Select the ion. -NO 2 -H2SO4 -AI + 3

25 In general, for a gas at a constant pressure, A the temperature of the gas is inversely proportional to its volume B. the temperature of the gas is inversely proportional to its pressure C.

The vapor pressure of ethanol is 54.68 mm Hg at 25 °C. A nonvolatile, nonelectrolyte that dissolves in ethanol is saccharin. Calculate the vapor pressure of the solution at 25 °C when 8.054 grams of saccharin, C7H5NO3S (183.

What do microscopic producers supply the atmosphere with?

A particular form of electromagnetic radiation has a frequency of 8.11 x 10^14 hz. What is the energy in joules of one quantum of this radiation?

Which transition elements in the first transition series have anomalous electron configurations?