6 13.A new home had a wooden floor put down in cool weather. As the weather became
warmer, the floor started to buckle, rising up in the middle of the floor. The floor was
fixed by trimming the edges of the floor so that there was a space between the flooring
and the wall. Choose the response that best explains why this helped to make the floor
flat again.
A. The particles in the floor decrease in thermal energy in warm weather, decreasing
the kinetic energy of its particles and making it expand. Trimming it gave it room to
expand
B. The particles in the floor increase in thermal energy in warm weather, increasing the
kinetic energy of its particles and making it expand. Trimming it gave it room to
expand.
C. The particles in the floor decrease in thermal energy in warm weather, decreasing
the kinetic energy of its particles and making it contract. Trimming it gave it room to
contract.
D. The particles in the floor increase in thermal energy in warm weather, increasing the
kinetic energy of its particles and making it contract. Trimming it gave it room to
contract.

Nconcentration refers to the molar concentration of an ion in solution. it may be identical to, or greater or less than, the molar concentration of the compound containing the ion that was used to make the solution. for soluble salts, the molarity of a particular ion is equal to the molarity of that compound times the subscript for that ion. for example, 1 m of alcl3 is 1 m in al3+ and 3 m in cl−. 1 m of (nh4)2so4 is 2 m in nh4+ and 1 m in so42−. part a what is the concentration of k+ in 0.15 m of k2s? view available hint(s) nothing m m part b if cacl2 is dissolved in water, what can be said about the concentration of the ca2+ ion? view available hint(s) if is dissolved in water, what can be said about the concentration of the ion? it has the same concentration as the cl− ion. its concentration is half that of the cl− ion. its concentration is twice that of the cl− ion. its concentration is one-third that of the cl− ion. part c a scientist wants to make a solution of tribasic sodium phosphate, na3po4, for a laboratory experiment. how many grams of na3po4 will be needed to produce 550 ml of a solution that has a concentration of na+ ions of 0.700 m ? express your answer numerically in grams. view available hint(s) mass of na3po4 n a 3 p o 4 = nothing g provide feedback

How do dying stars contribute to the formation of planets

The size (radius) of an oxygen molecule is about 2.0 ×10−10m. make a rough estimate of the pressure at which the finite volume of the molecules should cause noticeable deviations from ideal-gas behavior at ordinary temperatures (t= 300k ). assume that deviatons would be noticeable when volume of the gas per molecule equals the volume of the molecule itself.