When placed in a freezer, liquid water turns into solid ice. Why is this considered a physical change?

How some solutions can conduct electricity while others not?

4. The type of society that has the greatest energy needs is the __ A hunting society B agricultural society C industrial society D gathering society

Which volume, in cm3, of 0.20 mol dm-3 naoh (aq) is needed to neutralize 0.050 mol of h2s (g) ? h2s (g) + 2naoh (aq) → na2s (aq) + 2h2o (l) ?

Are the noble gases considered inert or reactive? Why?

4. You are preparing 250 mL of gel mix for protein electrophoresis, which requires a final concentration of 1.6% SDS. The lab has a 10% stock solution of SDS.

An aqueous solution is made from a molecular compound rather than from an ionic compound. If some ions are present in solution, which best describes the solute? A. a weak electrolyte B. a nonelectrolyte C. a strong electrolyte D.

Which of the following measures the radiation given off by atoms per second?

What is the name of the outermost layer that forms a boundary around the outside of each cell

What does an ionic compound form?

How many electrons in an atom could have these sets of quantum numbers n=7 l=3 ml=-1?