Chapter 2 The Chemical Basic of Life I: Atoms

If 3 grams of sodium chloride are dissolved in enough water to make 12 liters, what is the concentration of the solution?

0.25g/L

Each change of one pH unit represents a ______ difference in H+ concentrations.

10-fold

If an electron gains of loses a(n) _______, it acquires a net electrical charge and becomes an ion.

Electron

What type of bond occurs when a cation binds to an anion?

Ionic bond

An aqueous solution is one in which the solvent is

Water

The _______ of a solution is the negative base 10 logarithm of the H+ concentration of the solution.

pH

If the pH of a solution is 6, what is the concentration of protons?

10^-6 M

Carbon has 6 protons, 6 electrons, and 6 nucleus. What is its atomic mass?

12

Water, with the chemical formula H2O, contains ________ hydrogen atom(s) and ________ oxygen atom(s).

2, 1

Nitrogen had 5 electrons in its outer shell, so it can bond with up to ______ other atoms to complete its outer shell.

3

Which of the following best describes how a hydrogen bond forms?

A partially positive hydrogen atom and a partially negative atom in two polar molecules are attached by electrostatic interactions

Which of the following solutions contains the highest concentration of protons?

A solution with pH 2.0

A substance that releases hydrogen ions into solution is called a(n)

Acid

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

Acidic

A solution at pH 5 is said to be ______ because it contains more _______.

Acidic, H+ ions than OH- ions

Arrange the following solutions in order of increasing proton concentration. The solution with the lowest proton concentration should be placed at the top of the list.

Alkaline, neutral, acidic

The hydrogen bonds between water molecules form between:

An oxygen atom on one water molecules and a hydrogen atom on a second water molecule

Matter is composed of functional units called ________, two or more of which bonded together form a _______.

Atom, molecule

Which of the following describes the smallest functional unit of matter?

Atoms

A substance that absorbs hydrogen ions in solution is called a(n)

Base

Chemical reactions requires a source of energy and also may require a substance called a(n) ________ that speeds up the reaction rate. Most chemical reactions proceed toward a state called ________, in which the rate of product formation equals the rate of reactant formation.

Catalyst, equilibrium

An ion with a net positive charge is a(n):

Cation

An ionic bond forms when a positively charged ion, called a(n) _________, interacts with a negatively charged ions, called a(n) ________.

Cation, anion

The phenomenon of water molecules attracting one another is known as ________, whereas the process of water molecules being attracted to non-neutral surfaces is known as ________.

Cohesion, adhesion

The _______ of an atom is a measure of its ability to attract electrons when in a bond with another atom.

Electronegativity

What determines whether a covalent bond is polar or non-polar?

Electronegativity of the atoms involved in the bond

What type of subatomic particle is found outside the nucleus?

Electrons

Atoms are electrically neutral because they have equal numbers of _______ and ______.

Electrons, protons

Each specific type of atom is called a(n)

Element

The capacity to do work is known as:

Energy

Chemical _______ is reached when the rate of the forward reaction is equal to the rate of the reverse reaction.

Equilibrium

When water vaporizes at an ordinary temperature, the process is known as ___________.

Evaporation

True of False. Electrons are found in the atom's nucleus.

False

An element with a large mass contains _______ an element with smaller mass.

Fewer atoms per gram than

Select all of the following that are compounds. O2 HF NaCl H2 C6H12O6

HF, NaCl, C6H12O6

High specific heat, surface tension, and cohesion are several properties of water involving ________ bonds.

Hydrogen

The bond indicated by the arrow in the diagram is a(n) _______ bond.

Hydrogen

Why is energy required to separate two strands of DNA?

Hydrogen bonds must be broken

When water is heated, the rate at which _______ bonds break increases, and water molecules are converted to the ________ state.

Hydrogen, gaseous

In a(n) _______ reaction, water is used to break apart another molecule.

Hydrolysis

Amphipathic molecules have both _________ regions and _________ regions.

Hydrophobic, polar

Within an atom's structure, electrons can be found:

In cloud like orbials

An atom with a net electric charge is called a(n):

Ion

What property of water makes it a good solvent?

Its ability to form hydrogen bonds

An atom or ion is most stable when

Its outermost shell is occupied by its full complement of electrons

Elements have increasingly full orbitals as you look from:

Left to right on the periodic table

An element's atomic _______ is based on the protons and neutrons it contains, while an element's atomic ______ is based only on the number of protons.

Mass, number

Matter is anything that has _______ and occupies __________.

Mass, space

When mixed with water, amphipathic molecules may aggregate into spheres called _________.

Micelles

The number of moles of a solute dissolved in one liter of solution is the solution"s

Molarity

What term describes two or more atoms that are bonded together?

Molecule

Ions that have a net _______ charge are called anions.

Negative

Isotopes of an element differ from one another in the number of _________ they contain.

Neutrons

When micelles from, the interactions between water and the _______ regions of amphipathic molecules are minimized.

Non-polar

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

Non-polar covalent

Due to the presence of protons, an atom's _______ has a net positive electrical charge.

Nucleus

According to the _______ rule, atoms tend to be most stable when their outer shells are filled; this can be accomplished by gaining, losing, or sharing ________.

Octet, electrons

How many types of atoms can be found in a single element?

Only one

By mass, the most abundant element in living organism is:

Oxygen

When two water molecules are near each other, a hydrogen bond will form between the ________ and ______ atoms of neighboring water molecules.

Oxygen, hydrogen

A covalent bond in which the atoms share electrons unequally is a(n) ________ covalent bond.

Polar

A(n) _______ bond is formed when 2 atoms of different electronegativies share electrons.

Polar covalent

In a water molecule (H2O), each hydrogen atom has a partial ________ charge, and the oxygen atom has a partial ________ charge.

Positive, negative

Pure water can ionize into

Positively charged protons (H+) and negatively charged hydroxide (OH) ions

In the conversion of methane and oxygen to carbon dioxide and water, carbon dioxide is a(n):

Product

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

Proton

Atoms contain three types of particles, positively charged ______, negatively charged _______, and uncharged ________.

Protons, electrons, and neutrons

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

Protons, neutrons

Which of the following are considered subatomic particles?

Protons, neutrons, and electrons

In living organisms, the three states of matter are __________, _________, and ________.

Solid, liquid, and gas

The concentration of a liquid is defined as the amount of _______ dissolved in a unit volume of solution.

Solute

Substance dissolved in liquid are known as

Solutes

Solutes dissolved in a solvent form a(n):

Solution

A liquid that can dissolve substances is known as a(n)

Solvent

_______ _______ is a measure of the attraction between molecules of water at the surface of a liquid due to hydrogen bonding.

Surface tension

What is the heat of fusion of a substance?

The amount of heat energy released when 1 mole of the substance is converted from liquid to solid

What part of an amphipathic molecule would be oriented toward the center of a micelle?

The non-polar region

What is the molarity of a solution?

The number of moles of solutes in 1L

An atom's atomic number represents:

The number of protons

When a chemical reaction has reached equilibrium:

The rate of the formation of products equals the rate of the formation of reactants

The. molecular mass of a molecule is equal to:

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

Atoms are chemically the most stable when which of the following occurs?

Their outer shell is full

Atoms are most stable when:

Their outer shells are filled

Which of the following statements describe hydrophilic molecules?

They are solvable in water

Electrons in an atom's outermost energy shells are called __________ electrons

Valence