Thursday, September 17, 2015

Lesson 1, 2, and 3. Questions 1-8, 12-15, 20-29


Page 80:
1. All samples of a given substance have the same intensive properties because intensive properties look at the type of matter not how much of it there is. So all substances have the same intensive properties even if the amount of the substance changes.

2. Three states of matter: 
1. Solid 
2. Liquid
3. Gas

3. Two categories used to classify physical changes are reversible and irreversible. Boil, freeze, melt, and condense are reversible. Break, split, grind, cut, and, crush are irreversible. 

4. Two categories used to classify properties of matter are extensive properties and intensive properties. An intensive property is the type of matter and extensive properties are the amount of matter.

5. In the Physical Properties of Some Substances table you can most easily distinguish sodium chloride from the other solids by its melting point and boiling point. Many substances are solid and white but not all solid white substances melt at 801 degrees C or boil at 1413 degrees C.

6. Liquids and gases alike because they both move freely and they are both fluid, meaning they take the form of what ever they are inside of.  Liquids and solids are different because molecules in solids are more condensed than molecules in liquids because solids have definite shapes and volumes

7. The freezing of mercury is a reversible physical change because the Mercury can be melted until it is back to its original state. This is a physical change because the chemical make up stays the same even though it's state of matter may have changed.

8. Samples of platinum and copper can have the same extensive properties but not the same intensive properties because platinum and copper may have the same amount of mass per square unit, but their mass is made up of different things. 

Page 87:
12. Mixtures are classified by heterogeneous- separate and homogenous- together.

13. The types of properties that can be used to separate mixtures are filtration and distillation. Filtration a solid from a liquid in a heterogeneous mixture. Distillation can separate water from other components in tap water.

14. The term phase is used to describe any part of a sample with uniform composition. It relates to homogeneous and heterogeneous mixtures because a homogeneous mixture has only one phase because it is all one thing, a heterogeneous mixture has 2 or more phases because they are not "mixed" together.

15. Classify each of the following as a homogeneous or heterogeneous mixture.
a. food coloring: homogeneous 
b. ice cubes in liquid water: heterogeneous until ice melts
c. mouthwash: homogeneous 
d. mashed, unpeeled potatoes: heterogeneous 

Page 95:
20. If two clear liquids, A and B sit out and evaporate and there is a white solid still left in container B and nothing in container A I can infer that container B had a compound in it that separated when it evaporated and container A might have had an element that evaporated all together.

21. If a liquid is left out to evaporate and after three days there is a solid left in the container I can infer that the liquid was not an element because elements can not separate. This either means it was a compound that separated into elements or a mixture separated into compounds.

Page 100:
22. A compound different from an element be because a compound can be broken down into a smaller form: an element. An element can not be broken down any smaller.

23. You can distinguish a substance from a mixture because a substance has a fixed amount of materials and a mixture has variety of materials.

24. Chemical symbols are used to show elements and chemical formulas are used to show compounds.

25. The periodic table is such a useful tool because it makes it easier to compare elements and what they are. You can compare elements mass and atomic number.

26. Two methods that can be used to break down compounds into simpler substances are heat and electricity. Heating does not break down water. An electric current will, however, break down water into hydrogen and oxygen, but from there it can not be broken down any smaller because hydrogen and oxygen are element.

27. Classify each of these samples of matter as an element, a compound, or a mixture.
a. table sugar: compound 
b. tap water: mixture. Only pure H2O would be a compound
c. cough syrup: mixture 
d. nitrogen: element
28. Write the chemical symbol for each of the following elements:
a. lead: Pb
b. oxygen: O
c. silver: Ag
d. sodium: Na
e. hydrogen: H
f. aluminum: Al

29. Name the chemical elements represented by the following symbols
a. C: Carbon
b. Ca: Calcium 
c. K: Potassium 
d. Au: Gold
e. Fe: Iron
f. Cu: Copper 

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