A.7 (p.20 -21) #1-7 (only do #1 and 2)

6/21/13

1. 3,043 + 2,052.1 + 2,096.9 = 7,192 L used by my household in three days.

2. One member of my household used about 600 L of water on Day One.

3. A histogram of the class average per person.

4. The rang of the average daily personal water use within my class is 1,493 L.

5. The mean value of the class data is 600 L and the median value of the class date is 579. The mean is the better representation of the data set because it is the average, therefore, it is more accurate than the median.

6. The class average of the class is 600 L, and the average water use in the United States is 370 L. Some reasons I can propose to explain the difference between my value and the national average value is that the houses in our class may have bigger yards, and therefore need more water. Another reason why our water value is higher than the national average is because we live in a dessert, which requires us to use water all year long on our yards. Unlike places where is snows and rains.

7. The average of the class value is closer to the national average than the average water use by person daily because the average class water use is 579L  and the national average use is 370 L. The reason I can give for why the class average is closer to the national average is because there are a lot of people in each of the calculations.

Question: What do our results tell us?
-Our results tell us that the more people the lower the average per person is, and the less people the more the average per person is. It also tells us the that different activities in the house can either cause the water average to rise, or sometimes even lessen.

ISBS (p.50-52) #13-18

13. Model of a molecular compound made up of two atoms of A and one atom of D

 

14. 
     a) Models i, ii, iv, and vi represent models
     b) Models iii, iv, and v represent compounds

15. The two pieces of information a chemical formula provides is one it is a "word" that represents chemical substances. And two, it contains chemical symbols that represents each element, and subscripts that indicates how many atoms of an element are present in the substance.

16.
     a) Phosphoric acid (H₃PO₄): three hyrdrogen atoms, one phosphorus atom, and four oxygen atoms.
     b) Sodium hydroxide (NaOH): one sodium atom, one oxygen atom, and one hydrogen atom.
     c) Sulfer dioxide (SO₂): one sulfer atom, and two oxygen atoms

17.
    a) H₂ + Cl₂ --> 2 HCl

  b) 2 H₂O₂ --> 2 H₂O + O₂

    c) 17a: two hydrogen atoms + two chlorine atoms --> 2 hydrogen and chlorine. 17b: 2 compounds of hydrogen and oxygen atoms --> 2 compounds of two hydrogen atoms and one oxygen atom + two oxygen atoms.

18. Chemical equations that represents word equations
     a) NaHCO₃ + HCl --> NaCl + H₂0 + CO₂
     b) C₆H₁₂O₆ + 6 O₂ --> 6 CO₂ + 6 H₂O