BIOL 1201 - Exam 1 Questions and Answers Already Passed
A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n)
_____. - Answers element
Organisms are largely composed of __ elements. - Answers 11
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements
make up approximately 96% of living matter? - Answers carbon, hydrogen, nitrogen, and oxygen
What determines solubility? - Answers "like dissolves like"
Atom - Answers Smallest unit of matter that retains all the properties of that element
What is the mass and charge of protons? - Answers Mass: 1 Dalton
Charge: +1
What is the mass and charge of neutrons? - Answers Mass: 1 Dalton
No charge
What is the mass and charge of electrons? - Answers Mass: close to none (about 1/10000 that of a
proton or neutron)
Charge: -1
Which subatomic particle(s) always have a positive charge? - Answers protons
Atomic Number - Answers equal to the number of protons in an atoms
In a neutral atom, the atomic number is equal to... - Answers the number of protons
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons? - Answers 6
From its atomic number of 15, it is possible to predict that phosphorus always has ___. - Answers 15
protons
Atomic Mass - Answers the sum of the number of protons and neutrons in an atom
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have? -
Answers 10 neutrons
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons
does boron have? - Answers 5 protons
,Changing the number of _____ would change an atom into an atom of a different element. - Answers
protons
Isotopes - Answers variants of an atom that have different atomic masses due to differing numbers of
neutrons
What refers to atoms with the same atomic number but different atomic masses? - Answers isotopes
True or False: An atom with more neutrons than the atom described in the question above will have a
different valence. - Answers False
Where are protons located within an atom? - Answers the nucleus
Where are neutrons located within an atom? - Answers the nucleus
Where are electrons located within an atom? - Answers orbitals, or shells, around the nucleus of an
atom
What are the names of the first three electron orbitals and how many electrons do each of them
contain? - Answers K-shell: 2 electrons
L-shell: 8 electrons
M-shell: 8 electrons
An atom with the atomic number 9 will have _______ electrons in its outermost electron shell. -
Answers 7
Electrons always try to be in the ____ orbital or energy shell. - Answers lowest
Valence - Answers the number of electrons that either need to be gained or lost to fill the outermost
shell with electrons
What is significant about valence? - Answers Valence predicts the number of bonds that atoms will form
An atom with the atomic number 15 has a valence of __. - Answers 3
Valence Electrons - Answers electrons in the outermost shell of an atom
What is the difference between valence and valence electrons? - Answers Valence is the NUMBER of
electrons that either need to be gained or lost to fill the outermost shell with electrons, while valence
electrons are the ELECTRONS in the outermost shell of an atom
When are atoms the most stable and nonreactive? - Answers Atoms are stable and nonreactive when
their outer electron shells are full.
Why do atoms attempt to either gain or lose electrons? - Answers Atoms attempt to either lose or gain
electrons in order to fill their outer shells and become stable
, Chemical bonds are the result of ____________. - Answers electrical attractions between atoms that
either gain, lose, or share electrons
Ionic Bonds - Answers bonds that are the result of very strong electrical attractions, where electrons are
either lost or gained
An ionic bond involves _____. - Answers an attraction between ions of opposite charge
Ionic bonds are strongest when _____. - Answers they are dry
Atoms with the same number of protons but with different electrical charges _____. - Answers are
different ions
In salt, what is the nature of the bond between sodium and chlorine? - Answers ionic
Covalent Bonds - Answers bonds that are the result of electrical attractions that are not so strong, where
the electrons are shared
If electrons are shared equally, then the bond is known as a ________. - Answers pure covalent bond, or
non-polar covalent bond
If electrons are shared unequally, then the bond is known as a _____. - Answers polar covalent bond
What happens to the electrons in a polar covalent bond? - Answers The more electronegative atom has
the electrons more than the other atom, creating a slight charge negative charge where the electrons
spend the most time and a slight positive charge where the electrons spend the least amount of time.
These opposing charges hold the molecule together.
When are covalent bonds the strongest? - Answers in water
A(n) _____ refers to two or more atoms held together by covalent bonds. - Answers molecule
Compound - Answers a substance consisting of two or more different atoms, in specific proportions,
bonded together in a specific pattern
Molecule - Answers the smallest unit of a compound that retains all of the properties of that compound
What is the difference between non-polar covalent, polar covalent, and ionic bonds? - Answers position
of the electrons in time
100% around one nuclei: ionic
50% around each nuclei: non-polar covalent
75%/25% around one nuclei (approx.): polar covalent
A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n)
_____. - Answers element
Organisms are largely composed of __ elements. - Answers 11
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements
make up approximately 96% of living matter? - Answers carbon, hydrogen, nitrogen, and oxygen
What determines solubility? - Answers "like dissolves like"
Atom - Answers Smallest unit of matter that retains all the properties of that element
What is the mass and charge of protons? - Answers Mass: 1 Dalton
Charge: +1
What is the mass and charge of neutrons? - Answers Mass: 1 Dalton
No charge
What is the mass and charge of electrons? - Answers Mass: close to none (about 1/10000 that of a
proton or neutron)
Charge: -1
Which subatomic particle(s) always have a positive charge? - Answers protons
Atomic Number - Answers equal to the number of protons in an atoms
In a neutral atom, the atomic number is equal to... - Answers the number of protons
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons? - Answers 6
From its atomic number of 15, it is possible to predict that phosphorus always has ___. - Answers 15
protons
Atomic Mass - Answers the sum of the number of protons and neutrons in an atom
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have? -
Answers 10 neutrons
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons
does boron have? - Answers 5 protons
,Changing the number of _____ would change an atom into an atom of a different element. - Answers
protons
Isotopes - Answers variants of an atom that have different atomic masses due to differing numbers of
neutrons
What refers to atoms with the same atomic number but different atomic masses? - Answers isotopes
True or False: An atom with more neutrons than the atom described in the question above will have a
different valence. - Answers False
Where are protons located within an atom? - Answers the nucleus
Where are neutrons located within an atom? - Answers the nucleus
Where are electrons located within an atom? - Answers orbitals, or shells, around the nucleus of an
atom
What are the names of the first three electron orbitals and how many electrons do each of them
contain? - Answers K-shell: 2 electrons
L-shell: 8 electrons
M-shell: 8 electrons
An atom with the atomic number 9 will have _______ electrons in its outermost electron shell. -
Answers 7
Electrons always try to be in the ____ orbital or energy shell. - Answers lowest
Valence - Answers the number of electrons that either need to be gained or lost to fill the outermost
shell with electrons
What is significant about valence? - Answers Valence predicts the number of bonds that atoms will form
An atom with the atomic number 15 has a valence of __. - Answers 3
Valence Electrons - Answers electrons in the outermost shell of an atom
What is the difference between valence and valence electrons? - Answers Valence is the NUMBER of
electrons that either need to be gained or lost to fill the outermost shell with electrons, while valence
electrons are the ELECTRONS in the outermost shell of an atom
When are atoms the most stable and nonreactive? - Answers Atoms are stable and nonreactive when
their outer electron shells are full.
Why do atoms attempt to either gain or lose electrons? - Answers Atoms attempt to either lose or gain
electrons in order to fill their outer shells and become stable
, Chemical bonds are the result of ____________. - Answers electrical attractions between atoms that
either gain, lose, or share electrons
Ionic Bonds - Answers bonds that are the result of very strong electrical attractions, where electrons are
either lost or gained
An ionic bond involves _____. - Answers an attraction between ions of opposite charge
Ionic bonds are strongest when _____. - Answers they are dry
Atoms with the same number of protons but with different electrical charges _____. - Answers are
different ions
In salt, what is the nature of the bond between sodium and chlorine? - Answers ionic
Covalent Bonds - Answers bonds that are the result of electrical attractions that are not so strong, where
the electrons are shared
If electrons are shared equally, then the bond is known as a ________. - Answers pure covalent bond, or
non-polar covalent bond
If electrons are shared unequally, then the bond is known as a _____. - Answers polar covalent bond
What happens to the electrons in a polar covalent bond? - Answers The more electronegative atom has
the electrons more than the other atom, creating a slight charge negative charge where the electrons
spend the most time and a slight positive charge where the electrons spend the least amount of time.
These opposing charges hold the molecule together.
When are covalent bonds the strongest? - Answers in water
A(n) _____ refers to two or more atoms held together by covalent bonds. - Answers molecule
Compound - Answers a substance consisting of two or more different atoms, in specific proportions,
bonded together in a specific pattern
Molecule - Answers the smallest unit of a compound that retains all of the properties of that compound
What is the difference between non-polar covalent, polar covalent, and ionic bonds? - Answers position
of the electrons in time
100% around one nuclei: ionic
50% around each nuclei: non-polar covalent
75%/25% around one nuclei (approx.): polar covalent
