Chapter 3 Definitions

___ has an overall positive or negative charge.

An ion

An atom as a whole
has a net ___ of zero.

electric charge

___ can gain and
lose energy in increments.

Electrons

In ___, a positive and a negative ion are linked by the mutual attraction of the opposite charge.

an ionic bond

In a nonpolar covalent bond, one or more electrons are ___.

shared equally between atoms

In a hydrogen bond, an electronegative atom ___.

weakly attracts a hydrogen
atom that is covalently
bonded to a different atom

A substance whose molecules
___ is an acid.

release hydrogen ions
in a solution

A substance that ___ is a base.

combines with hydrogen
ions in a solution

Next to water, ___ are the
main inorganic compounds
present in the cell.

salts

A salt is ___.

a compound that has been
formed by the reaction between
an acid and a base.

When two simple sugar
molecules become covalently bonded through condensation,
the result is ___.

a disaccharide

A simple carbohydrate
is made of only: ___.

carbon, hydrogen and oxygen

___ are an assortment of
oily or waxy substances.

Lipids

A solution having a pH less than seven is ___.

acidic

If pH is greater than seven
the solution is ___.

basic

Pure water has a pH of ___.

7

The most acidic pH is ___.

0

The most basic pH is ___.

14

___ is the enzyme-mediated
cleavage of a molecule
into two or more parts
by reaction with water.

Hydrolysis

In a polar covalent bond, one
or more electrons are ___.

shared unequally between atoms

No two elements have the same
number of ___ in their atoms.

protons

A mass number is the ___.

total number of protons
and neutrons in the nucleus

In a covalent bond, ___.

one or more electrons
are shared between atoms.