BIO 1100 Unit 2 questions
What is an atom? What are subatomic particles?
The Atom is the basic unit of a chemical element; a source of nuclear energy; a basic building
block of matter; and cannot be chemically divided. In contrast, Subatomic particles are smaller
than actual atoms.
What are neutrons? Protons? Electrons? Atomic nucleus?
Protons, neutrons, and electrons are the subatomic particles of an atom.
Protons located inside the nucleus; positively charged; the number of protons is the atomic
number and determines a chemical identity and chemical properties; cannot be changed by
chemical reactions (only nuclear reactions can affect these).
Neutrons also located inside the nucleus; Neutral/has NO charge; atoms containing extra
neutrons are ‘heavy’ and unstable radioactive isotopes which can decay by shooting neutrons
and/or energy out at high speed.
Number of protons + number of neutrons = Atomic mass
Electrons found in the electron cloud valence shell, orbit the nucleus at the speed of light in
the electron cloud; negatively charged; small and weight is negligible. Electrons do not travel in
fixed orbits, but whiz around the nucleus erratically in a so-called electron cloud;
donated/accepted or shared to form a chemical bond; having more or fewer electrons creates an
electrical charge and creates an Ion; an atom with an equal number of negatively charged protons
is electrically neutral.
What are valence shells? What is the octet rule?
The valence shell refers to the outermost electron shell of an atom. A valence shell/ring or
electron shell; contains a set number of electrons. 1st shell contains up to 2 electrons, and 2nd shell
can contain up to 8 electrons. If the valence shell is full that means the atom is stable. If the
valence shell is not full, the atom is reactive; meaning it will tend to react with other atoms in
ways that make the valence shell full.
The Octet Rule states that an atom will give up, gain, or share electrons with another atom so
that it ends up with eight electrons in its valence shell.
The first shell must be filled before electrons can reside in the second, which must be filled
before electrons can reside in the third.
What are isotopes?
Isotopes are forms of an element that have different numbers of neutrons. All isotopes of an
element have the same atomic number and number of protons, but they have different atomic
masses from each other. Isotopes of an element share similar chemical properties, but have
, different nuclear properties. Isotopes are the elements with extra neutrons. These are radioactive.
Atomic weight varies between isotopes, but atomic number does not.
What is the atomic number? Atomic mass? What is the difference between them?
The atomic number is the number of protons in an atom while atomic mass is the sum of some
protons and some neutrons.
This determines the chemical identity of an element.
What is a pure element? A compound?
A pure element is a substance that cannot be broken down through a chemical reaction.
A compound Is formed when two or more atoms are joined together by chemical bonding; When
a molecule is made up of two or more atoms of different elements,
Atoms are stable when their outermost shell (valence shell) is full. To make this happen, atoms
can donate, accept, or share electrons, and this process is called chemical bonding.
What is a cation? Anion? Dissociation? Electrolytes?
Ion An atom that has an electrical charge—whether positive or negative—is an ion.
Cation positively charged ion.
Anion negatively charged ion.
Dissociation Dissociation is the separation of ions that occurs when a solid ionic compound
dissolves.
Electrolytes The electrical activity that derives from the interactions of the charged ions.
What is an ionic bond? What role or how are electrons part of this bond?
The ionic bond is an ongoing, close association between ions of opposite charge. It occurs when
a metal donates one or more electrons to a non-metal, creating charged ions called salts; a
transfer of electrons always results in salts in this scenario.
What is a covalent bond? What role or how are electrons part of this bond?
Molecules formed by a covalent bond share electrons in a mutually stabilizing relationship. The
atoms do not lose or gain electrons permanently. Instead, the electrons move back and forth
between the elements. Because of the close sharing of pairs of electrons (one electron from each
of two atoms), covalent bonds are stronger than ionic bonds. Covalent bonds can either be polar
or non-polar.
What is a nonpolar covalent bond? A polar covalent bond?
Non-polar covalent bond unequal sharing.
What is an atom? What are subatomic particles?
The Atom is the basic unit of a chemical element; a source of nuclear energy; a basic building
block of matter; and cannot be chemically divided. In contrast, Subatomic particles are smaller
than actual atoms.
What are neutrons? Protons? Electrons? Atomic nucleus?
Protons, neutrons, and electrons are the subatomic particles of an atom.
Protons located inside the nucleus; positively charged; the number of protons is the atomic
number and determines a chemical identity and chemical properties; cannot be changed by
chemical reactions (only nuclear reactions can affect these).
Neutrons also located inside the nucleus; Neutral/has NO charge; atoms containing extra
neutrons are ‘heavy’ and unstable radioactive isotopes which can decay by shooting neutrons
and/or energy out at high speed.
Number of protons + number of neutrons = Atomic mass
Electrons found in the electron cloud valence shell, orbit the nucleus at the speed of light in
the electron cloud; negatively charged; small and weight is negligible. Electrons do not travel in
fixed orbits, but whiz around the nucleus erratically in a so-called electron cloud;
donated/accepted or shared to form a chemical bond; having more or fewer electrons creates an
electrical charge and creates an Ion; an atom with an equal number of negatively charged protons
is electrically neutral.
What are valence shells? What is the octet rule?
The valence shell refers to the outermost electron shell of an atom. A valence shell/ring or
electron shell; contains a set number of electrons. 1st shell contains up to 2 electrons, and 2nd shell
can contain up to 8 electrons. If the valence shell is full that means the atom is stable. If the
valence shell is not full, the atom is reactive; meaning it will tend to react with other atoms in
ways that make the valence shell full.
The Octet Rule states that an atom will give up, gain, or share electrons with another atom so
that it ends up with eight electrons in its valence shell.
The first shell must be filled before electrons can reside in the second, which must be filled
before electrons can reside in the third.
What are isotopes?
Isotopes are forms of an element that have different numbers of neutrons. All isotopes of an
element have the same atomic number and number of protons, but they have different atomic
masses from each other. Isotopes of an element share similar chemical properties, but have
, different nuclear properties. Isotopes are the elements with extra neutrons. These are radioactive.
Atomic weight varies between isotopes, but atomic number does not.
What is the atomic number? Atomic mass? What is the difference between them?
The atomic number is the number of protons in an atom while atomic mass is the sum of some
protons and some neutrons.
This determines the chemical identity of an element.
What is a pure element? A compound?
A pure element is a substance that cannot be broken down through a chemical reaction.
A compound Is formed when two or more atoms are joined together by chemical bonding; When
a molecule is made up of two or more atoms of different elements,
Atoms are stable when their outermost shell (valence shell) is full. To make this happen, atoms
can donate, accept, or share electrons, and this process is called chemical bonding.
What is a cation? Anion? Dissociation? Electrolytes?
Ion An atom that has an electrical charge—whether positive or negative—is an ion.
Cation positively charged ion.
Anion negatively charged ion.
Dissociation Dissociation is the separation of ions that occurs when a solid ionic compound
dissolves.
Electrolytes The electrical activity that derives from the interactions of the charged ions.
What is an ionic bond? What role or how are electrons part of this bond?
The ionic bond is an ongoing, close association between ions of opposite charge. It occurs when
a metal donates one or more electrons to a non-metal, creating charged ions called salts; a
transfer of electrons always results in salts in this scenario.
What is a covalent bond? What role or how are electrons part of this bond?
Molecules formed by a covalent bond share electrons in a mutually stabilizing relationship. The
atoms do not lose or gain electrons permanently. Instead, the electrons move back and forth
between the elements. Because of the close sharing of pairs of electrons (one electron from each
of two atoms), covalent bonds are stronger than ionic bonds. Covalent bonds can either be polar
or non-polar.
What is a nonpolar covalent bond? A polar covalent bond?
Non-polar covalent bond unequal sharing.
