CH 2 Supplemental Learning Flashcards
Orbitals are best described as __________.
a three-dimensional space where an electron spends most of its time with no more than 1 other electron, forming a pair
Although all forms of life require _____, other elements are required only by certain species.
iron
When a very electronegative atom strips a valence electron away from its partner, __________ form.
ions
weak chemical bonds where there is an attraction between a hydrogen atom and an electronegative atom.
Hydrogen bonds
weak chemical reaction that occurs only when atoms and molecules are very close together.
“Van der Waals interactions
the sharing of a pair of valence electrons by two atoms.
Covalent bonds
the sharing of a pair of valence electrons by two atoms, where one of the atoms is strongly electronegative.
Polar covalent bonds
Because of their opposite charges, cations and anions attract each other; this attraction is called an
ionic bond.
In some cases, two atoms are so unequal in their attraction for valence electrons that the more electronegative atom strips an electron completely away from its partner. The two resulting oppositely charged atoms (or molecules) are called
ions.
What has negligible mass?
Electron -is not taken into account for atomic mass calculations
Hydrogen bonds are noncovalent bonds that result from an attraction between a hydrogen molecule that is already covalently bonded to an electronegative atom, and another electronegative atom. Hydrogen bonds thus form between molecules with partial opposite charges.
Hydrogen bonds occur when partial opposite charges on molecules come close enough to attract each other
A covalent bond is likely to be polar if __________.
one of the atoms sharing electrons is much more electronegative
If the atoms sharing electrons are equally electronegative, the electrons are shared equally and the bond is
nonpolar.
This would be the case, for example, for two atoms of the same element.
Trace elements __________.
are required by an organism in minute quantities
______ lead to changes in the composition of matter by making and breaking chemical bonds.
chemical reactions
_______ exists when the forward and reverse rates of the reaction are equal; it does not depend on the amounts or concentrations of reactants and products.
Chemical equilibrium
Because matter is being neither created nor destroyed, the number of particular atoms on either side of the reaction equation is
always the same.
Any reactive atom or molecule that can react, not just organic molecules, can participate in a chemical reaction.
Any reactive atom or molecule that can react, not just organic molecules, can participate in a chemical reaction.
Weak chemical bonds such as hydrogen bonds __________.
form when a hydrogen atom that is covalently bonded to an electronegative atom like oxygen or nitrogen is attracted to another electronegative atom
both oxygen and nitrogen are _______ electronegative atoms.
strongly
hydrogen ______ an electronegative atom.
is not
_______ bonds are important in biological systems.
hydrogen
When the proton number and electron number are unequal, the atom or molecule __________.
is an ion
Isotopes of an element will always differ in __________.
atomic mass
The atom has more electrons than protons.
Anion
A ____ is an atom that has more protons than electrons and carries a positive charge
cation
The difference between a stable isotope and an unstable isotope of an element is that __________.
the unstable isotope has a nucleus that decays spontaneously, is radioactive, and can be transformed into an atom of another element
Stanley Miller’s experiments were significant because he demonstrated that _________
a variety of simple organic compounds could be spontaneously synthesized from components in Earth’s primitive atmosphere
A straight-chain carbon compound constructed from __________ must contain at least one carbon-carbon double bond.
6 hydrogen atoms and 3 carbon atoms
Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they __________.
share the same functional group: a hydroxyl
Functional group: Its compounds may be structural isomers with different properties.
carbonyl group
Two carboxyl groups can bond covalently to help stabilize protein structure
sulfhydryl group.
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.
carboxyl group.
The functional groups is associated with a release of energy when removed from the carbon skeleton with water?
Phosphate group
Which functional group would you predict is part of abscisic acid?
Carboxyl group
Compounds containing the _______functional group (—COOH) are known as carboxylic acids or organic acids. They can donate a hydrogen ion (proton) to a solution due to a highly polar oxygen atom of the functional group.
Compounds containing the carboxyl functional group (—COOH) are known as carboxylic acids or organic acids. They can donate a hydrogen ion (proton) to a solution due to a highly polar oxygen atom of the functional group.
The elements carbon, hydrogen, nitrogen, and oxygen make up ____% of living mass.
96%
There are ___naturally occurring elements, and about ____ of these are essential to human life.
There are 92 naturally occurring elements, and about 25 of these are essential to human life.
When one or more pairs of valence electrons are shared by two neutral atoms, what type of bond is formed?
Covalent bonds are formed between atoms that share one or more pairs of valence electrons.
Pharmaceutical researchers are often interested in blocking particular receptor proteins on cell surfaces. What chemical property of a molecule would be most important for this type of application?
The molecule’s shape
describe a reversible reaction that has reached chemical equilibrium?
The rate of the reverse reaction equals the rate of the forward reaction.
