Ch. 2 chemistry homework

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

A. has both polar and non polar

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.

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.

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.

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.

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.

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

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

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

a. glucose

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

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

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

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

b. organic

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 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

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

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

c. decomposition

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

c. salt

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

d. all of the above

__________ 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