Calcium atoms have two electrons in the outermost shell. As a result, you would expect calcium to form ions with a charge of

A) + 1.

B) + 2.

C) - 1.

D) - 2.

E) 0.

If a sample of nitrogen gas (N2) contains 3.0 x 104 atoms of nitrogen, then about how many moles of nitrogen gas are in the sample?

Why is carbon an important element in the chemistry of organisms? (hint: it's about the number of bonds)

Part b what is the maximum mass, in grams, of nh3 that can be produced by the reaction of 1.0 g of n2 and 1.0 g of h2 using the reaction below? n2+h2? nh3 (not balanced)

Which headings should be used to complete this table? R-OHR -o-R R-C- R O= R -C-H R -C-OH R-C-0-R' 0 Beverages Fuel Anesthetic Weak acid Organic solvent Organic solvent Preservative Adhesive Vinegar Fats Fragrances compound (top row);

Magnetite and hematite are both ores for which element?

Two clear solutions are placed in separate beakers. The first solution has a pH of 4, and the pH of the second solution is unknown. If the two solutions are mixed and the resulting pH is 5, the second solution must have

Based on its location on the periodic table, which element (s) have properties similar to N? Choose all that apply. * P C O Bi

What conclusion can be drawn from the statement that an element has low electron affinity, low electronegativity, and a low ionization energy?

A scientist performs an experiment in which a radium-226 (Ra-226) atom decays into radon-222 (Rn-222). The scientist concludes that some energy must have been added to the system to cause this reaction to begin.

Which suitable method can be used to separate a mixture of sand and paraffin