Bio 200- The Chemical Basis Of Life

Front 1

A substance that cannot be broken down to other substances by chemical means is a(n) __________ .

Back 1

Element

Front 2

A solution at pH 6 contains ____ times more H+ than the same amount of solution at pH 8.

Back 2

A solution at pH 6 contains 100 times more H+ than the same amount of solution at pH 8.

Front 3

True or False: Most of the unique properties of water result from the fact that water molecules tend to stick together?

Back 3

True.

Front 4

Define "element"

Back 4

A substance that cannot be broken down to other substances by chemical means.

Front 5

Define "atom".

Back 5

The smallest unit of matter that retains the properties of an element.

Front 6

True or False: table salt, water, and carbon are compounds.

Back 6

False. Only table salt and water are compounds.

Front 7

A chemical compound that donates H+ ions to solutions is called a(n) _________.

Back 7

acid

Front 8

A liquid consisting of a homogeneous mixture of two or more substances is a(n) __________.

Back 8

solution

Front 9

What is an ion?

Back 9

An ion is a charged particle that is akin to an atom.

Front 10

True or False: The pH scale is set up so that pure water has a pH of 1.

Back 10

False. The pH scale is set up so that pure water has a pH of 7.

Front 11

If the atoms in a molecule share electrons equally, the molecule is said to be _______.

Back 11

nonpolar

Front 12

True or False: Atoms in a water molecule are held together by the sharing of electrons.

Back 12

True

Front 13

True or False: "Temperature" is a measure of the average kinetic energy or speed of molecules in a substance.

Back 13

True.

Front 14

True or False: table salt, water, and chlorophyll are compounds.

Back 14

True.

Front 15

When electrons are shared equally during bonding, the bond is said to be ___________.

Back 15

nonpolar

Front 16

What is "cohesion"?

Back 16

Cohesion is the tendency of molecules to stick together.

Front 17

True or False: "Heat" is a measure of the average kinetic energy or speed of molecules in a substance.

Back 17

False. Temperature is a measure of the average kinetic energy or speed of molecules.

Front 18

Explain electronegativity.

Back 18

The tendency for an atom to pull electrons towards itself. The more electronegative an atom, the more strongly it pulls shared electrons toward itself, increasing polarity.

Front 19

True or False: A "polar covalent bond" is a chemical bond in which shared electrons are pulled closer to one atom than the other.

Back 19

True

Front 20

Your body contains the smallest amount of which of the following:
a) nitrogen
b) phosphorus
c) carbon
d) oxygen
e) hydrogen

Back 20

Your body contains more oxygen than carbon, more carbon than hydrogen, more hydrogen than nitrogen, and more nitrogen than phosphorus. b) phosphorus is the answer, and makes up 1% of the human body.

Front 21

True or False: Most of the unique properties of water result from the fact that water molecules are held together by covalent bonds.

Back 21

False. Most of the unique properties of water result from the fact that water molecules stick together.

Front 22

True or False: Water is neither polar nor nonpolar because the hydrogen atom is nonpolar, and the oxygen atoms are polar.

Back 22

False. Water is polar.

Front 23

True or False: "Heat" is the amount of energy associated with the movement of the atoms and molecules in a body of matter.

Back 23

True.

Front 24

What is "surface tension"?

Back 24

Surface tension is a measure of how difficult it is to stretch or break the surface of a liquid.

Front 25

In a tall tree, water in thin tubes within the trunk is pulled upward by evaporation from the leaves. What keeps the water molecules at the bottom of the tree moving upward?

Back 25

Hydrogen bonds hold neighboring water molecules together in the liquid water. This "cohesion" helps the molecules move against the downward pull of gravity.

Front 26

True or False: "Temperature" is the amount of energy associated with the movement of the atoms and molecules in a body of matter.

Back 26

False. Heat is the amount of energy associated with the movement of the atoms and molecules in a body of matter.

Front 27

The attractive or repulsive forces between molecules other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral molecules are known as _____________.

Back 27

Van Der Waals Forces

Front 28

Attractions between molecules that are close together, that result from asymmetric electron clouds are known as ____________.

Back 28

Van Der Waals Forces

Front 29

How do buffers work?

Back 29

They accept H+ ions from an additive when in excess, and donate H+ ions to an additive when depleted.