What is the density of iridium metal? (Ir: 192.2 g/mol; face-centered cubic with 3.83x10^-8 cm edges).

What do a mole of magnesium (Mg) and a mole of iron (Fe) have in common? A. their number of atoms B. their number of molecules C. their number of electrons D. their number of protons

Which property is common to noble gases? A. Strong odor B. Low reactivity C. Brightly colored D. High reactivity

Calcium is an element. What is the smallest particle of calcium that has all the chemical properties of calcium?

What is a large groove or channel in the soil that carries runoff after rainstorm?

Ground water has some minerals dissolved in it. If you heat this water, collect the vapor in another container, and then cool it, you will get pure, or distilled, water. What makes this process a physical change?

If object A is placed on the pH scale at pH = 3 and object B is placed at pH = 8, which of the following must not be true? A. Object B has a higher hydroxide ion concentration than object A. B. Object B is closer to a neutral pH than object A. C.

Laboratory safety is not an important concern for scientists. True or false

Which of the bonding forces from the list below would need to be overcome to convert NH3 from a liquid to a gas? (Enter the letters in order of all that apply, e. g. AB, ABD, ACDE, etc.

A precipitate of zinc hydroxide can be formed using the reaction below. ZnCl2 (aq) + 2 KOH (aq) → Zn (OH) 2 (s) + 2 KCl (aq) If excess KOH is used, the zinc hydroxide will form zincate ions and dissolve in the solution according to the chemical

Which of the following is the correct (unbalanced) equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide? A. P (s) + O2 (g) - -> P2O5 (s) B. P2O5 (s) - -> P2 (s) + O2 (g) C.