Fill in the Blank

1. Mixture Fill in the Blank Na Na Na Cl Cl Cl O O O O O O O O O H H H H H H Is this a mixture or pure substance? ______________________

2. False, there are only two (water & salt) True or False Salt Water Na Na Na Cl Cl Cl O O O O O O O O O H H H H H H This mixture contains three compounds. ________________________________

3. True True or False Cl Cl Cl O O O O O O O O O Cl Cl H H H H H H H H H There are ten molecules in this mixture. _____________ Cl N

4. Oxygen Fill in the Blank Na Na Na Cl Cl Cl Cl O O O O O O O O H H H H H H H H H H Oxygen Below is a mixture of compounds and elements. What is the element? ___________________ Oxygen N

5. Drawing How many bonds can carbon form? Four bonds C Draw a model of CH4. H H H H

6. Multiple choice O O O O C C C C C C C C A B H H H H H H H H H H H H H H H Which is the correct configuration for the compound C2H3OH? H C D

7. Drawing O C H H H H Draw the structure for CH3OH?

8. Element or Compound? Carbon Oxygen Carbon dioxide Hydrogen Water C Element OElement CO2 Compound H Element H2O Compound Indicate whether each the following substances is an element or compound.

9. Element or Compound? Salt Water (distilled) Seawater Sugar Salad dressing Pure substance Pure substance Mixture Pure substance Mixture Indicate whether each the following substances is a mixture or pure substance.

10. Short Answer + Proton (positive) Electron (negative) Neutron (neutral) Name the three particles that make up atoms and indicate their charge.

11. Outside the nucleus Inside a proton Within the nucleus Inside a neutron Multiple Choice + + Where are electrons found in an atom?

12. Multiple Choice + + 2 3 5 7 What is the mass number of the atom shown below?

13. Multiple Choice + + + + + B. C. Which nuclei is not an isotope of the other two?

14. Short Answer + + + 3 What is the atomic number of the atom shown below?

15. Multiple Choice Isotope Compound Nucleus Enzyme Which of the following is a substance formed by the chemical joining of two or more elements in definite amounts, like H2O

16. Multiple Choice O O O O O O H H H H H H B. C. D. Which of the following represents the best model of a water molecule?

17. Yes or No Δ + When the elements sulfur and iron are mixed and heated in a test tube, they react to form iron pyrite (fool’s gold). Would you expect iron pyrite to retain the magnetic properties of iron or the smell of sulfur? Fool’s gold Iron Sulfur Chemical reactions rearrange atoms into new substances with different properties. No

18. Short Answer A covalent bond. Because the atoms are sharing the electrons. What kind of chemical bond is shown below and how do you know?

19. Short Answer + + + + A positive ion. What type of ion is formed when an atom loses an electron?

20. Short Answer What property of water enables water to cling to the surface of a glass or to a toothpick? Adhesion, which means molecules of different substances are attracted to each other.

21. Multiple Choice O O O O ( ) ( ) H H H H H H H H ( ) ( ) Which shows the correct polarity of a water molecule? B. C. D.

22. Short Answer What kind of mixture is paint or blood? They are suspensions, which means they contain particles that will eventually settle out.

23. Short Answer In our blood, the enzyme carbonic anhydrase carries out the following reactions in order to prevent sharp, sudden changes in blood pH. What kind of system is this? Carbonic anhydrase A buffer system

24. Short Answer What property of water enables insects and paper clips to float on its surface? Cohesion, which means molecules of the same substance are attracted to each other.

25. Short Answer An ionic bond. Because the electron was completely transferred from one atom to another rather than being shared. What kind of chemical bond is shown below and how do you know? This causes each atom to develop a charge (become an ion).

26. Short Answer What kind of mixture is air or salt water? They are solutions, because all the components are evenly distributed.

27. Short Answer Which has the higher heat capacity—water, metal, or air? Water does. It can absorb a lot of heat without its temperature rising too much.

28. Matching Which pH values would you assign to the following chemicals: • Pure water • Stomach juice • Oven cleaner • Lemon juice • Soap 7 1 to 2 13 to 14 2 to 3 9 to 10

29. Short Answer Is this liquid acidic, basic, or neutral? How do you know? Neutral Because there is an equal number of H+ ions and OH- ions.

30. Drawing Draw a model of carbon dioxide. O O C How many double bonds does carbon dioxide have? Two double-bonds

31. Drawing Draw a model of acetylene (C2H2). C C H H What kind of bond is this? A triple bond

32. Short Answer A 3-month old sits strapped in a car seat on a hot July day because her dad forgot she was in the car. Her body temperature climbs to 105 °F (41 °C). What may happen to the enzymes in her body if her temperature continues to climb? Her enzymes will unravel (denature) and she will die.

33. Drawing Draw an amino acid. O N C C R Carboxyl group Amino group H H H H Variable group Label the functional groups.

34. Short Answer Is this liquid acidic, basic, or neutral? How do you know? Basic Because there are more OH-ions than H+ ions in solution.

35. Short Answer Complete the following table Amino acid Polysaccharide Nucleic acid

36. Short Answer What reagent is used to test for proteins? Biuret's solution What color does Biuret’s turn if proteins are present? Lavender topurple

37. Short Answer What is another name for monosaccharides? Simple sugars

38. Short Answer What reagent is used to test for simple sugars? Benedict’s solution What color does benedict’s turn if simple sugars are present? Yellowto orange

39. Short Answer Complete the following table Sucrose Glycogen Cellulose Glucose Maltose Fructose

40. Short Answer In what polysaccharide do animals store their excess sugars? Glycogen

41. Short Answer In what polysaccharide do plants store their excess sugars? Starches

42. Short Answer What reagent is used to test for starches? Lugol’s (iodine) solution What color does Lugol’s turn if starches are present? Purple to Black

43. Short Answer What polysaccharide gives plants their rigidity and support? Cellulose

44. Short Answer Complete the following table ATP Single Stranded RNA Storing hereditary Info Double-helix DNA

45. Short Answer What does the abbreviation DNA stand for? Deoxyribonucleic acid

46. Short Answer What does the abbreviation ATP stand for? Adenosine triphosphate

47. Drawing Draw and label a simple model of a triglyceride lipid. 3 Fatty-acid tails Glycerol

48. Short Answer Is this liquid acidic, basic, or neutral? How do you know? Acidic Because there are more H+ions than OH- ions in solution.

49. Short Answer What happens to the chemical bonds in a chemical reaction? Some bonds are broken and new ones are formed.

50. Short Answer What happens to the atoms in a chemical reaction? Atoms are never destroyed but only rearranged into new combinations.