2. Cell Chemistry & Cell Components
,2. Cell Chemistry & Cell Components
CONCEPT: ATOMS - SMALLEST UNIT OF MATTER
● blank : anything that takes up space & has mass (ex. organisms, rocks, oceans, etc.).
□ All matter consists of at least 1 chemical blank .
● Chemical Elements: pure substances made of only one type of blank .
□ Atom: the blank unit of an element (& therefore, the smallest unit of matter).
□ Atoms makes up both blank & blank matter.
EXAMPLE: Atoms are the Smallest Units of Matter.
Atomic Structure
●Atoms are made of blank subatomic particles, each with a characteristic charge, mass & location in the atom.
EXAMPLE: Negatively charged particles of atoms with almost no mass are called:
a) Electrons. b) Protons. c) Neutrons. d) Ions. e) Polymers.
PRACTICE: A proton blank :
a) Has one positive charge. b) Has one AMU. c) Is found in the nucleus of the atom.
d) Only a and b are true. e) a, b, and c are true.
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,2. Cell Chemistry & Cell Components
CONCEPT: ATOMS - SMALLEST UNIT OF MATTER
Elements of Life
●Of all the known elements, only a blank subset is found in living organisms.
□ Periodic Table of blank : arranges all of the known elements based on their chemical properties.
●~97% of the mass of most life is composed of Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus & Sulfur (CHNOPS).
□ blank Elements: required for life in blank amounts.
EXAMPLE: Periodic Table of Elements.
Atomic Properties
●Each atom of an element has unique properties:
□ blank Number: # of blank in the nucleus (atomic number blank each element).
□ blank Number: mass of the nucleus (# of blank & blank ).
□ Atomic mass (or atomic blank ) = blank total mass of all atoms of an element.
EXAMPLE: Atomic Properties of a Carbon Atom.
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, 2. Cell Chemistry & Cell Components
CONCEPT: ATOMS - SMALLEST UNIT OF MATTER
EXAMPLE: The atomic number of an element is equal to the number of:
a) Neutrons only. b) Protons plus electrons. c) Protons plus neutrons.
d) Neutrons plus electrons. e) Protons only.
PRACTICE: The average oxygen atom has a mass number of 16 and an atomic number of 8. This means that the number
of neutrons in this oxygen atom is:
a) 24. b) 8. c) 16. d) 4. e) 2.
Electron Orbitals & Energy Shells
● Electron blank : 3D-regions around a nucleus where electrons are found (envisioned in 2D as energy shells).
□ Shells closer to the nucleus are blank in energy than distant shells, which are higher in energy.
□ Valence Electrons: electrons found in the blank energy shell (valence shell).
□ 1st shell holds up to blank electrons; 2nd shell holds up to blank electrons; each shell holds varying #’s.
EXAMPLE: Energy Shells for C, H, N, O, P, S.
PRACTICE: How many valence electrons does an atom with five total electrons have?
a) 5. b) 7. c) 3. d) 2. e) 1.
PRACTICE: Which of the following is true about electron energy shells?
a) They represent regions around the nucleus in which the electrons orbit.
b) The shells closest to the nucleus contain electrons with higher energy.
c) They contain electrons of the same energy.
d) a and b only.
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,2. Cell Chemistry & Cell Components
CONCEPT: ATOMS - SMALLEST UNIT OF MATTER
● blank : anything that takes up space & has mass (ex. organisms, rocks, oceans, etc.).
□ All matter consists of at least 1 chemical blank .
● Chemical Elements: pure substances made of only one type of blank .
□ Atom: the blank unit of an element (& therefore, the smallest unit of matter).
□ Atoms makes up both blank & blank matter.
EXAMPLE: Atoms are the Smallest Units of Matter.
Atomic Structure
●Atoms are made of blank subatomic particles, each with a characteristic charge, mass & location in the atom.
EXAMPLE: Negatively charged particles of atoms with almost no mass are called:
a) Electrons. b) Protons. c) Neutrons. d) Ions. e) Polymers.
PRACTICE: A proton blank :
a) Has one positive charge. b) Has one AMU. c) Is found in the nucleus of the atom.
d) Only a and b are true. e) a, b, and c are true.
Page 2
,2. Cell Chemistry & Cell Components
CONCEPT: ATOMS - SMALLEST UNIT OF MATTER
Elements of Life
●Of all the known elements, only a blank subset is found in living organisms.
□ Periodic Table of blank : arranges all of the known elements based on their chemical properties.
●~97% of the mass of most life is composed of Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus & Sulfur (CHNOPS).
□ blank Elements: required for life in blank amounts.
EXAMPLE: Periodic Table of Elements.
Atomic Properties
●Each atom of an element has unique properties:
□ blank Number: # of blank in the nucleus (atomic number blank each element).
□ blank Number: mass of the nucleus (# of blank & blank ).
□ Atomic mass (or atomic blank ) = blank total mass of all atoms of an element.
EXAMPLE: Atomic Properties of a Carbon Atom.
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, 2. Cell Chemistry & Cell Components
CONCEPT: ATOMS - SMALLEST UNIT OF MATTER
EXAMPLE: The atomic number of an element is equal to the number of:
a) Neutrons only. b) Protons plus electrons. c) Protons plus neutrons.
d) Neutrons plus electrons. e) Protons only.
PRACTICE: The average oxygen atom has a mass number of 16 and an atomic number of 8. This means that the number
of neutrons in this oxygen atom is:
a) 24. b) 8. c) 16. d) 4. e) 2.
Electron Orbitals & Energy Shells
● Electron blank : 3D-regions around a nucleus where electrons are found (envisioned in 2D as energy shells).
□ Shells closer to the nucleus are blank in energy than distant shells, which are higher in energy.
□ Valence Electrons: electrons found in the blank energy shell (valence shell).
□ 1st shell holds up to blank electrons; 2nd shell holds up to blank electrons; each shell holds varying #’s.
EXAMPLE: Energy Shells for C, H, N, O, P, S.
PRACTICE: How many valence electrons does an atom with five total electrons have?
a) 5. b) 7. c) 3. d) 2. e) 1.
PRACTICE: Which of the following is true about electron energy shells?
a) They represent regions around the nucleus in which the electrons orbit.
b) The shells closest to the nucleus contain electrons with higher energy.
c) They contain electrons of the same energy.
d) a and b only.
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