Ch. 2 Questions

Nitrogen has an atomic number of seven. How many electron shells does it likely have? a. one b. two c. three d. four

b. two

Which of the following is a molecule, but not a compound? a. H20 b. 2H c. H2 d. H+

c. H2

Explain why CH4 is one of the most common molecules found in nature. Are the bonds between the atoms ionic or covalent?

CH is an organic compound, therefore found in larger amounts (ie. acids and bases). This would make it an ionic bonds.

Could two atoms of oxygen engage in ionic bonding? Why or why not?

The same element would have identical electronegativity, therefore it cannot engage in ionic bonding.

Oxygen, whose atomic number is 8, has three stable isotopes: 16O, 17O and 18O. Explain what this means in terms the number of protons and neutrons.

In oxygen, since the atomic number is 8 that means there are 8 protons. Isotopes are distinguished from an element by the number of neutrons.

What happens when water encounters a glycosidic bond?

The glycosidic bond changes from a disaccharide to two monosaccharides.

CH4 is methane. The compound is ___________. a. inorganic b. organic c. reactive d. a crystal

b. organic

Uracil ___________. a. contains nitrogen b. is a pyrimidine c. is founding RNA d. all of the above

d. all of the above

Which of the following statements about chemical bonds is true? a. covalent bonds are stronger than ionic bonds. b. hydrogen bonds occur between two atoms of hydrogen. c. bonding readily occurs between non polar and polar molecules. d. a molecule of water is unlikely to bond with an ion.

a. covalent bonds are stronger than ionic bonds

The bonding of calcium, phosphorus, and other elements produces mineral crystals that are found in bone. This is an example of a(n) __________ reaction. a. catabolic b. synthesis c. decomposition d. exchange

b. synthesis

AB -> A + B is a general notation for a(n) ______ reaction. a. anabolic b. endergonic c. decomposition d. exchange

c. decomposition

The most abundant elements in the foods and beverages you consume are oxygen, carbon, hydrogen, and nitrogen. Why might having this elements in consumables be useful?

As humans, we have to eat and drink to stay alive. We need nutrients, plus we get hungry and thirsty. This is an easy way to consume the elements we need. It's like killing 2 birds with 1 stone.

C6H12O6 is the chemical formula for a ______________ a. polymer of carbohydrate b. pentose monosaccharides c. hexose monosaccharides d. all of the above

a. a polymer of carbohydrate

When an atom donates an electron to another atom, it becomes a. an ion b. an anion c. non polar d. all of the above

a. an ion

What organic compound do brain cells primarily rely on for fuel? a. glucose b. glycogen c. galactose d. glycerol

a. glucose

Which of the following combinations of atoms is most likely to result in a chemical reaction? a. hydrogen and hydrogen b. hydrogen and helium c. helium and helium d. neon and helium

a. hydrogen and hydrogen

The energy stored in a foot of snow on a steep roof is ________. a. potential energy b. kinetic energy c. radiant energy d. activation energy

a. potential energy

The characteristic that gives an element its distinctive properties its number of _______________. a. protons b. neutrons c. electrons d. atoms

a. protons

Which of the following is most likely to be found evenly distributed in water in a homogenous solution? a. sodium ions and chloride ions b. NaCl molecules c. salt crystals d. red blood cells

a. sodium ions and chloride ions

Ty is three years old and as a result of a "stomach bug" has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean? a. Ty's blood is slightly acidic. b. Ty's blood is slightly alkaline. c. Ty's blood is highly acidic d. Ty's blood is within the normal range

b. Ty's blood is slightly alkaline

A phospholipid ________________. a. has both polar and non polar regions b. is made up of a triglyceride bonded to a phosphate group c. is a building block of ATP d. can donate both cations and anions in solution

b. is made up of a triglyceride bonded to a phosphate group

A pentose sugar is part of the monomer used to build which type of macromolecule? a. polysaccharides b. nucleic acids c. phosphorylated glucose d. glycogen

b. nucleic acids

A substance formed of crystals of equal numbers of cations and anions held together by ionic bonds is called a(n) __________. a. noble gas b. salt c. electrolyte d. dipole

b. salt

The ability of an enzyme's active sites to bind only substrates of compatible shape and charge is known as ____________. a. selectivity b. specificity c. subjectivity d. specialty

b. specificity

Which of the following is a functional group that is part of a building block of proteins? a. phosphate b. adenine c. amino d.ribose

c. amino

On the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59.It has seven stable isotopes. The most abundant these probably have _______. a. about 80 neutrons each b. fewer than 80 neutrons each c. more than 80 neutrons each d. more electrons than neutrons

c. more than 80 neutrons each

A molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. These are linked with _____________. a. ionic bonds b. nonpolar covalent bonds c. polar covalent bonds d. hydrogen bonds

c. polar covalent

A substance dissociates into K+ and Cl- in solution. The substance is a(n) ______________. a. acid b. base c. salt d. buffer

c. salt

__________ reactions release energy. a. catabolic b. exergonic c. decomposition d. catabolic, exergonic, and decomposition

d. catabolic, exergonic, and decomposition

In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n)____________. a. beta chain b. pleased sheet c. alpha helix d. double helix

d. double helix

Together, just four elements make up more than 95 percent of the body's mass. These include ___________. a. calcium, magnesium, iron, and carbon b. oxygen, calcium, iron, and nitrogen c. sodium, chlorine, carbon, and hydrogen d. oxygen, carbon, hydrogen, and nitrogen

d. oxygen, carbon, hydrogen, and nitrogen

Chewing a bite of bread mixes it with saliva and facilitates its chemical breakdown. This is most likely due to the fact that ___________. a. the inside of the mouth maintains a very high temperature b. chewing stores potential energy c. chewing facilitates synthesis reactions d. saliva contains enzymes

d. saliva contains enzymes

Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate chip batter is an example of a ________. a. solvent b. solute c. solution d. suspension

d. suspension

AB + CD -> AD + BE Is this a legitimate example of an exchange reaction? Why or why not?

No, the reactants are not re-arranged, instead there are added reactants (E). The correct reaction should be AB + CD -> AD + BC.

When you do a load of laundry, why do you not just drop a bar of soap into the washing machine? In other words, why is laundry detergent sold as a liquid or powder?

It takes energy to separate particles of a substance. Powder and liquid laundry detergents, with relatively more surface area per unit, can quickly dissolve into their reactive components when added to the water.

The pH of lemon juice is 2, and the pH of orange juice is 4. Which of these is more acidic, and by how much? What does this mean?

Lemon juice is more acidic than orange juice. On the pH scale, 7 is neutral. Therefore, 2 is farther away from 7 the 4 is on the scale.

During a party, Eli loses a bet and is forced to drink a bottle of lemon juice. Not long thereafter, he begins complaining of having difficulty breathing and his friends take him to the local emergency room. There, he is given an intravenous solution of bicarbonate. Why?

Lemon juice, like any acid, releases hydrogen ions in solution. As excessive H+ enters the digestive tract and is absorbed into blood, Eli's blood pH falls below 7.35. Recall that bicarbonate is a buffer, a weak base that accepts hydrogen ions. By administering bicarbonate intravenously, the emergency department physician helps raise Eli's blood pH back toward neutral.

If the disaccharide maltose is formed from two glucose monosaccharides, which are hexose sugars, how many atoms of carbon, hydrogen, and oxygen does maltose contain and why?

Maltose contains 12 atoms of carbon, but only 22 atoms of hydrogen and 11 atoms of oxygen, because a molecule of water is removed during its formation via dehydration synthesis

What happens to the charged electroscope when a conductor is moved between its plastic sheets, and why?

Nothing. In the example, a pen was used. The electrons in the pen did not change the plastic sheets on the electroscope because the plastic acted as an insulator.

Once dietary fats are digested and absorbed, why can they not be released directly into the bloodstream?

The dietary fats are digested and absorbed with the help on enzymes before getting released into the bloodstream as bigger particles cannot be absorbed. The fats are made up of single fatty acids or three fatty acid chains bonded to a single molecule called glycerol. Fats can be harmful as well as beneficial. Saturated and Trans fats are harmful dietary fat whereas mono and ply saturated are dietary fats are beneficial.

The smallest unit of an element that still retains the distinctive behavior that element is an ______________. a. electron b. atom c. elemental particle d. isotope

b. atom

Magnesium is an important element in the human body, especially in bones. Magnesium's atomic number is 12. Is it stable or reactive? Why? If it were to react with another atom, would it be more likely to accept or donate one or more electrons?

Magnesium is reactive according to the Octet rule. If it were to react with another element, it would most likely donate an electron, creating Mg + (cation)

In the periodic table of the elements, elements in a single column have the same number of electrons that can participate in a chemical reaction. These electrons are known as "valence electrons." For example, the elements in the firstwolumn all have a single valence electron- an electron that can be "donated"in a chemical reaction with another atom. What is the meaning of a mass number showing parenthesis?

The mass number is the sum of the number of protons and neutrons its nucleus.

In a hurry one day, you merely rinse your lunch dishes with water. As you are drying your salad bowl, you notice that it still has an oily film. Why was the water alone not effective in cleaning the bowl?

Water is a polar molecule. It has a region of weakly positive charge and a region of weakly negative charge. These regions are attracted to ions as well as to other polar molecules. Oils are nonpolar, and are repelled by water.