Ch 2 BIO 1200

compared with liquid water, ice has :

-a more orderly arrangement of water molecules -greater hydrogen bonds between individual water molecules

molecules that are predicted to easily dissolve in water

-carbohydrates that contain -OH groups -ions that carry full electric charges

Describe molecules that ONLY have hydrophobic regions.

-contain many nonpolar covalent bonds -relatively insoluble in water -dissolve well in nonpolar solvents

Arrange these solutions in order of increasing proton concentration (lowest at top) -neutral, alkaline, acidic

1. alkaline 2. neutral 3. acidic

Rank each state of water in order of increasing density, starting with the least dense state at the top of the list.

1. water vapor 2. ice 3. liquid water

If a solution has a pH of 8, what is the concentration of protons in the solution?

10^-8 M

Carbon has six protons, six electrons, and six neutrons. What is it's atomic mass?

12 (protons + neutrons)

A mole of an element contains:

6.022 x 10^23 atoms

Why is the atomic mass of carbon reported in the periodic table slightly greater than its predicted mass?

Because of the presence of a small amount of heavier isotopes

True or false: Matter exists in only one of two states: solid or liquid

False

A base will absorb _______ ions in solution

Hydrogen

If a person travels from the Earth to the Moon, which has less gravitational pull, how will their mass and weight be affected?

Mass will be the same but their weight will be different

What type of bonds are most likely to be found in a hydrophobic molecule?

Nonpolar covalent

In a micelle, which portion of the amphipathic molecules are oriented to the surface of the sphere?

The polar region

when do atoms tend to be more stable?

When their outer shells are filled with electrons

In pure water what are the concentrations of H+ and OH-?

[H+] = 10^-7 M [OH-] = 10^-7 M

solvent

a liquid that can dissolve other substances

aqueous solution

a solution in which water is the solvent

base

absorbs hydrogen ions in solution

If you add H+ ions to a solution, it becomes more:

acidic

a solution with a pH below 7

acidic

Cohesion

aids the movement of fluids through plant vessels

A solution with a pH above 7

alkaline

high heat of vaporization

allows animals to cool themselves through evaporation

surface tension

allows some insects to walk on the surface of the water without sinking

Adhesion

allows water to coat the surface of the digestive track

molecules containing a hydrophilic region and a hydrophobic region

amphipathic

an ion with a net negative charge

anion

a solution made with water

aqueous solution

The fundamental unit of matter is the

atom

A mole of any substance contains the same number of particles as there are:

atoms in exactly 12g of carbon; in Avogadro's number

living organisms minimize changes in their internal pH using compounds called:

buffers

Which medical applications rely on the injection of radioisotopes into the body?

cancer therapy, PET scans

Which four elements make up approximately 95% of living matter?

carbon hydrogen nitrogen oxygen

an ion that has a net positive charge

cation

the rate of formation of products equals the rate of formation of reactant

chemical equilibrium

a molecule composed for two or more different elements

compound

the amount of a solute dissolved in a unit volume of solution

concentration

a chemical bond in which two atoms share a pair of valence electrons

covalent bonds

One _____ equals 1/12 the mass of a carbon atom

dalton

hydrophilic molecules

dissolve in water; water loving

In the periodic table, the elements in the same row have the same number of:

electron shells

A measure of the ability of an atom in a chemical compound to attract electrons to its outer shell from another atom

electronegativity

Which type of subatomic particle is found outside the nucleus?

electrons

Each specific type of atom is called an

element

The capacity to do work is known as:

energy

True or false: An element is made up of two or more atoms

false

An element with a larger mass contains _____ an element with a smaller mass

fewer atoms per gram than

High specific heat, surface tension, and cohesion are several properties of water involving what type of bonds?

hydrogen

hydrochloric acid is considered an acid because it releases _____ ions into the solution

hydrogen

forms when a hydrogen atom from one polar molecule becomes electrically attracted to an electronegative atom in another polar molecule

hydrogen bond

a chemical reaction that utilizes water to break apart molecules

hydrolysis reaction

water loving

hydrophilic

Amiphipathic molecules have both ______ and ______ regions.

hydrophilic and hydrophobic

water fearing

hydrophobic

at atom or molecule that gains or loses one or more electrons and acquires a net electric charge

ion

Molecules are likely to dissolve easily in water if they contain what type of bonds?

ionic or polar covalent bonds

an element that exists in multiple forms that differ in the number of neutrons they contain

isotopes

Elements have increasingly full orbitals as you look from:

left to right on the periodic table

Which component of humans has the greatest percent of water?

lungs: 90%

An element's atomic _____ is based on the protons and neutrons it contains

mass

Matter is anything that has ____ and takes up ____.

mass; space

the sphere formed by long amphipathic when they are mixed with water

micelle

number of moles of a solute dissolved in 1 L of water

molarity

The sum of the atomic masses of all the atoms in a molecule.

molecular mass

how can substance dissolve in water?

must be electrically attracted to water molecules

pH is defined as the _____ _____ to the base 10 of the _____ ion concentration

negative; logarithm; hyrogen

Electron

negatively charged; located outside the nucleus

Isotopes of the same element differ in their number of:

neutrons

a covalent bond in which the electrons are shared equally by the two atoms

nonpolar covalent bond

hydrophobic molecules tend to contain many

nonpolar covalent bonds

Due to the presence of protons, an atom's _____ has a net positive electric charge

nucleus

An element's atomic _____ is based only on the number of protons

number

Valence electrons are found in:

outermost energy shells

The polar groups of a micelle are oriented toward the _____, while its nonpolar groups are oriented toward the _____.

outside; inside

Which solution contains the highest concentration of protons? -pH 7 -pH 5 -pH 8 -pH 10 -pH 2

pH 2

unequal sharing of electrons

polar covalent bond

Pure water can ionize into

positively charged protons (H+) and negatively charged hydroxide (OH-) ions

Proton

positively charged; located in the nucleus

the end result of a chemical reaction

product

colligative properties

properties of a solution that depend strictly on the total number of dissolved solutes and not the specific type of solute

Atoms of different chemical elements can be differentiated based on the number of which subatomic particle?

proton

An atom's atomic number is based on the number of _____ it contains

protons

Which two particles are the primary determinants of an element's atomic mass?

protons, neutrons

Which of the following are considered subatomic particles?

protons, neutrons, and electrons

an isotope found in nature that is inheritely unstable and usually does not exist for long periods of time; decay and emit energy in the form of radiation

radioisotopes

a substance that participates in a chemical reaction and becomes changed by that reaction

reactant

acid

releases hydrogen ions into solution

Substances dissolved in a liquid

solute

A solution is composed of _______ dissolved in a ________.

solutes; solvent

a liquid that contains one or more dissolved solutes

solution

the liquid in which a solute is dissolved

solvent

Substance A has a higher specific heat than substance B. With all other factors equal, which requires the most energy to heat equal masses of A and B to the same temperature?

substance A

solute

substances dissolved in a liquid

A solution at pH 6 is more acidic than a pH 7 because?

the concentration of H+ (protons) is 10x higher

heat of vaporization

the heat energy required to convert 1 mole of a substance from liquid to gas

specific heat

the heat energy required to raise the temperature of 1 gram of a substance by 1 degree celsius

heat capacity

the heat energy required to raise the temperature of an entire object

heat of fusion

the heat energy that must be withdrawn or released from a substance to convert it from liquid to solid

Why are atoms electrically neutral?

there are equal numbers of protons and electrons

Elements are electrically neutral because:

there are equal numbers of protons and electrons in a given atom

Carbon shares the most similar bonding properties with silicon because:

they share the same number of valence electrons

Why do micelles form?

to minimize interactions of nonpolar regions of molecules with water

A molecule is composed of

two or more atoms bonded together

Neutron

uncharged; located in the nucleus

Unpaired _____ electrons enable chemicals bonds to form among atoms

valence

evaporation

vaporization of water; helps animals dissipate body heat

hydrolysis reaction

water is used to break apart another molecule

When does an ionic bond occur?

when a cation binds to an anion