Bio166 Review Q Chapter 2

Anions and cations can form what bond? A: covalent B: hydrogen C: peptide D: ionic

ionic

If a molecule has 6 protons, 8 neutrons, and 6 electrons, its charge is _________ and its mass number is __________. A: 6, 6 B: 6, 12 C: 2, 12 D: 0, 12 E: 0, 14

0, 14

The strongest base will have a pH value of

14

The innermost shell of an atom can hold how many electrons? A: 0 B: 2 C: 8 D: 10 E: 16

2

Carbon has _________ electrons in its valence shell. A: 2 B: 4 C: 6 D: 8

4

Which statements describe sodium atoms? Select all that apply. A : contains 1 valence electron B : easily forms covalent bonds : can lose one electron easily C : can lose one electron easily D : forms cations E : closest to the left side of the periodic table F : has 2 electrons in the first energy level G : outer energy level is stable

A : contains 1 valence electron C : can lose one electron easily D : forms cations E : closest to the left side of the periodic table F : has 2 electrons in the first energy level

Which statements describe chlorine atoms? Select all that apply. A : contains 7 valence electron B : easily forms ionic bonds C : can gain one electron easily D : forms anions E : in Group 18 of the periodic table F : has 2 electrons in the first energy level G : outer energy level is stable

A : contains 7 valence electron B : easily forms ionic bonds C : can gain one electron easily D : forms anions F : has 2 electrons in the first energy level

A(n) _____ is a compound that yields hydrogen ions when dissolved in a solution.

Acid

What property of water allows it to move across paper towels? A: adhesion B: cohesion C: surface tension D: solvent E: adhesion and cohesion

Adhesion

A(n)_________ is a compound that yields hydroxide ions when dissolved in a solution.

Base

Baking soda can be swallowed to combine with excess hydrogen ions. Baking soda acts as a _______

Buffer

Which molecule(s) would dissolve in water based on polarity? Select all that apply. A : CH4 B : C2H6 C : C5H10O5 D : C6H6 E : CH3CH2 CH2 CH2 CH2 CH2OH

C : C5H10O5 E : CH3CH2 CH2 CH2 CH2 CH2OH

What element can form the most covalent bonds? A: Hydrogen B: Carbon C: Sodium D: Oxygen E: Nitrogen F: Chloride

Carbon

Hydrogen atoms attach to water through _____ bonds. Water molecules are cohesive because of _____ bonds.

Covalent Hydrogen

Your colleague working at NASA thinks he may have discovered life on Mars! But they look very different from life on Earth. "Mars has a different elemental composition than Earth," he tells you, "so we should expect Martian life to have elements in the same proportions as found in the planet's crust." What is your response to this idea? A: Earth organisms do not have elements in the same proportion as the Earth's crust. B: He must be wrong, because living organisms on Mars would have to be chemically similar to organisms on Earth. C: He is correct - the Martian organisms should be composed of elements in the same proportion as in the Mars crust. D: Organisms on Earth contain most of the elements of the Periodic Table in moderate proportions - not necessarily reflective of proportions in the Earth's crust

Earth organisms do not have elements in the same proportion as the Earth's crust.

A chemical bond occurs when __________________ are shared or transferred between molecules. A: Protons B: Neutrons C: Electrons

Electrons

True/False:Polar covalent bonds result when valence electrons are shared equally between 2 atoms.

False- electrons are not shared equally in polar bonds (eg., H2O).

Each carbon molecule can bind with as many as _________other atom(s) or molecule(s). A) One B) Two C) Four D) Six

Four

Which elements are common to all living organisms? A: H, P, S, N B: H, O, P, N C: H, C, O, N D: H, C, O, S

H, C, O, N

Electronegativity increases as it moves across the periodic table from left to right. Based on electronegativity, __________ bond would be non-polar. A: HCl B: CO C: H2 D: BrCl E: PF F: increases by 50 fold

H2

Which type of bond represents a weak chemical bond? A) Hydrogen bond B) Ionic bond C) Covalent bond D) Nonpolar covalent bond

Hydrogen bond

Carbon-12, Carbon-13, and Carbon-14 are examples of A: isomers. B: molecules. C: ions. D: isotopes. E: enantiomers.

Isotopes.

Why is salt (NaCl) used to slow ice forming? A: NaCl disrupts ice formation by interfering with hydrogen bonds B: NaCl contributes to the density of the ice C: NaCl has a lower freezing point D: more hydrogen bonds are formed from the addition of NaCl

NaCl disrupts ice formation by interfering with hydrogen bonds

Almost the entire mass of an atom is concentrated in the A) Proton B) Electrons C) Nucleus D) Neutrons

Nucleus

Atoms are considered stable when the outermost shells have eight electrons. This is the _______ rule.

Octet

Since oxygen is more electronegative than hydrogen, water is ___

Polar

_____ are subatomic particles with a positive charge.

Protons

______ allows paper clips to float on water even though it is more dense.

Surface tension

Your new study buddy is frustrated. "Why are we studying chemistry?" he grumbles. "I thought this was biology class!" What is your reply? A: Chemistry was an earlier science than biology, dating all the way back to the alchemists, therefore it is important that we study chemistry first. B: Success in any subfield in biology requires knowing what is happening chemically, down to the atoms. C: The activities inside a cell depend on a complex series of chemical interactions, so understanding chemistry helps you understand how cells work. D: The main reason for learning chemistry is because dangerous chemicals are stored in labs - it's just a safety concern.

The activities inside a cell depend on a complex series of chemical interactions, so understanding chemistry helps you understand how cells work.

Carbon represents less than 1% of the Earth's crust, but is 18% of the composition of living things. Why? A: Living organisms sequester carbon to lower its toxicity to their cells. B: Cytoplasm is composed largely of a liquid form of carbon. C: Cell membranes are composed of layers of graphite. D: The unique bonding properties of carbon allow it to create a huge variety of biological molecules. E: This is a measure of waste gases like CO2 and CH4.

The unique bonding properties of carbon allow it to create a huge variety of biological molecules.

Your biology professor says "On the one hand, chemistry helps us understand the interactions between molecules that are the basis of cellular function. On the other hand, most of the periodic table is completely irrelevant to understanding biology." What does she mean? A: Only 92 of the 118 elements are common in living cells - the rest occur rarely. B: Elements act differently when they are within a living cell. C: The vast majority of the molecules in living organisms are composed of just four elements. D: The periodic table reflects the rules of inorganic chemistry - but living organisms use organic chemicals.

The vast majority of the molecules in living organisms are composed of just four elements.

Valence electrons will determine an atom's chemical reactivity. A: True B:False

True

Which of the following statements is not true? A) Water is polar. B) Water is the near universal solvent. C) Water is hydrophilic. D) In solid form, water is less dense than in liquid form E) Water is the most abundant molecule in Earth's atmosphere.

Water is the most abundant molecule in Earth's atmosphere.

As water vaporizes, energy is ___________ from the environment. This process ____________ the surrounding environment. A: released; heats B: released; cools C: absorbed; heats D: absorbed; cools

absorbed; cools

What property of carbon makes it so important in the formation of molecules in life? A: carbon is able to form up to 4 covalent bonds B: carbon is considered inorganic C: carbon is a high energy atom D: carbon is only used to date living organisms

carbon is able to form up to 4 covalent bonds

What atom does not occur in large amounts in living organisms? Select all that apply. A : carbon (C) B : oxygen (O) C : cobalt (Co) D : hydrogen (H) E : copper (Cu)

cobalt (Co) copper (Cu)

When the number of hydrogen ions increases, the pH: A: increases. B: decreases. C: stays the same

decreases

If functional groups are removed from a molecule and only hydrogen and carbon remains, the molecule is now a A: carbonyl. B: carboxyl. C: hydrocarbon. D: carbohydrate.

hydrocarbon

The cohesive property of water is due to: A: hydrogen bonds. B: ionic bonds. C: covalent bonds.

hydrogen bonds

When atoms share electrons and electrons spend more time with one atom, what bond is formed? A: ionic bond B: peptide bond C: polar covalent bond D: nonpolar covalent bond E: hydrogen bond

polar covalent bond

The nucleus of an atom is normally composed of: A: protons and electrons. B: protons and neutrons. C: protons only. D: electrons only. E: neutrons only.

protons and neutrons.

How can ice float? A: the covalent bonds expand, decreasing density B: the hydrogen bonds expand, decreasing density C: the covalent bonds collapse, increasing density D: the hydrogen bonds collapse, increasing density

the hydrogen bonds expand, decreasing density

Weak interactions that may occur between any two molecules close to one another are: A: hydrogen bonds. B: ionic bonds. C: covalent bonds. D: van der Waals interactions.

van der Waals interactions