Chapter 2: Chemistry Flashcards
Biology is a _______ science.
multidisciplinary
_________ consists of chemical elements in pure form and in compounds
matter
T/F Matter consists of chemical elements in impure or pure forms and in mixtures
False
T/F Elements cannot be broken down to other substances by physical reactions, but they can be broken down by chemical reactions
False
A substance consisting of two or more different elements combined in a fixed ratio:
compound
___________ consists of chemical elements in pure form and in compounds
matter
NaCl and H20 are examples of ______
compounds
The four essential elements of life that make up 99% of living matter
Carbon, Oxygen, Hydrogen, Nitrogen
P, S, Ca, K and a few other elements make up ____ of all living matter
4 % of all living matter
P, S, Na, and K: which element does not belong (per lecture)?
Na (should be Ca)
What does an element’s properties depend upon?
The structure of its atoms
T/F a carbon atom retains the properties of elemental Carbon
True
A neutron’s charge and weight:
A proton’s charge and weight:
An electron’s charge and weight:
0 charge (1 amu) \+1 charge (1 amu) -1 charge (1/2000 amu)
Which two subatomic particles have the highest mass?
Neutron and proton
The _______ number is made up of the electron number and the proton number
atomic
The _____ number is composed of the proton number and the neutron number
mass number
If you add the proton number and electron number, what do you get?
The atomic number
T/F Isotopes behave differently in reactions
False
You find a carbon isotope. You predict that it will behave identically to a different Carbon isotope. Why do you predict this?
Different isotopes of a given element all have the same number of electrons and share a similar electronic structure. Because the chemical behavior of an atom is largely determined by its electronic structure, different isotopes exhibit nearly identical chemical behavior.
Do radioactive isotopes decay spontaneously?
Yes
Radioactive isotopes are unstable and give off _____ and ______
particles and energy
The capacity to cause change:
energy
Energy is the capacity to cause ______
chnge
What facet of electrons determines an electron’s potential energy?
Energy level
T/F An electron’s place in an energy shell determines its potential energy
False (an electron’s place in an energy level determines its potential energy)
T/F Energy level of electrons determines an electron’s potential energy
True
Can Electrons reside in an electron shell?
Yes
The more _______ an electron is from the nucleus, the greater its potential energy
distant
If an electron loses energy, it will go ______ the atomic nucleus
closer to
The more distant an electron is from the nucleus, the greater its
potential energy
The third energy shell is the _____ energy level in a 3-shell energy model:
highest
A ball bounding down a flight of stairs provides an analogy for energy levels of electrons
True
T/F When one electron absorbs energy, it may jump up into a shell that is farther from the nucleus
True
Periodic table of the elements:
Row: _______ numbers
Column: _______ in the outer shell
Row: shell numbers
Column: electrons in the outer shell
As you grow across columns, the ______ in the _____ _______ (for a given element) increase
electrons in the outer shell (for a given element) increase
As you go down a row, the _____ _____ will increase, meaning how far an electron is from the nucleus also increases (for elements further down a row)
shell number
T/F Electrons tend to exist in the highest available state of potential energy
False
Given the choice of a higher or lower state of potential energy, which state would an electron prefer to exist in?
Lower state of potential energy
You are studying electrons in the outermost shell of a Carbon atom. What is a common term for these electrons?
Valence shell electrons
The outermost shell of a carbon atom is called what?
valence shell
You are studying an element with a full valence shell t the far right of the periodic table. What is the proper categorical name for this atom?
Inert atom (noble gas)
Give three examples of noble gases (or inert atoms) in this category:
Helium, neon, and argon
Draw a box-picture of Helium and label the placement of the Atomic number, Mass number, Element symbol.
Atomic number (far left), Mass number (below symbol)
The 3D space where an electron is found 90% of the time:
a. Electron orbital
T/F An orbital is a component of an electron shell
True
Remember: each electron shell contains electrons at a particular energy level, distributed among a specific number of orbitals of distinctive shapes and orientations
You know it
T/F No more than 3 electrons can occupy a single orbital
False. No more than 2 electrons can occupy a single orbital
What arises from the presence of unpaired electrons in one or more orbitals of their valence shells?
Reactivity of atoms
_____ _____: 3D space where an electron is found 90% of the time
electron orbital
Each electron shell contains electrons at a particular _____ level, distributed among a specific number of ______ of distinctive shapes and ______
energy, orbitals, orientations
What is a component of an electron shell (as described in lecture)?
Electron orbit
What is a component of an electron shell (as described in lecture)?
Electron orbit
Noble gases are ____ gases
inert
As you go down the rows, you increase the ____
shell
Forming / function of molecules depend on ______ bonds between atoms
chemical
2 atoms sharing a pair of valence electrons
covalent bonds
You find two chloride atoms that share a pair of valence electrons. What is the name for this type of bond?
Covalent
What is the difference between covalent bonds and a molecule?
A covalent bond is bond formed between two atoms that share electrons. A molecule is composed of two atoms which share a covalent bond.
What is the difference between a compound and a molecule?
Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements. All compounds are molecules, but not all molecules are compounds.
2 (or more) atoms held together by covalent bonds:
Share 1 pair of valence electrons
Share 2 pairs of valence electrons
single bond
double bond
A molecule made of atoms from different elements
compound
H2, 02, H20, CH4
Which of these are also compounds?
molecules (covalent bonds)
H20 and Ch4
The attraction of a particular atom for the electrons of a covalent bond
Electronegativity
Electronegativity refers to the attraction of a particular ____ for the electrons of a _____ bond:
atom, covalent
The more electronegative an atom, the more its shared electrons go more strongly…where?
Its shared electrons are pulled toward the atom
T/F The less electronegative an atom, the more strongly it pulls shared electrons
False
T/F The less electronegative an atom, the more strongly it pulls shared electrons
False
Name two examples of non-polar covalent bonds that were mentioned in lecture
H2 O2
H20 is an example of a —– bond
polar covalent bond
In a non-polar bond, are electrons shared equally?
Yes
Why are polar covalent bonds so polar?
Differences in electronegativity
This bond is characterized by electron transfers between two atoms:
Ionic bond
an atom which loses an electron
cation
an atom which gains an electron
anion
In an ionic bond, the atom which gains an electron is known as the ______, and the atom which loses an electron is known as the ______.
anion, cation
T/F Ionic compounds can consist of molecules
False
Name one specific example of an ionic compound that was mentioned in lecture
NaCl
T/F The environment does not affect the strength of an ionic bond
False
Ions are entire molecules that are electrically charged
True
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Ion
____ bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds. It is one of the main bonds along with Covalent bond and Metallic bonding.
ionic bonding
T/F a molecule with non-polar covalent bonds may have positively and negatively charged regions
True
Electrons are not ____ distributed even n a molecule. What does this make atoms do?
evenly, atoms stick together
What determines how biological molecules recognize and respond to one another with specificity?
shape
If you have an s orbital and three p orbitals, you may form four _____ ______ which will have this shape:
four hybrid orbitals, tetrahedron
What is the degree amount between hydrogens bonded to oxygen on a H20 molecule
104.5
____ ____ is crucial in biology because it determines how biological molecules recognize and respond to one another with specificity:
molecular shape
What recognizes the same but specific shapes?
receptor
T/F There is a relationship between molecular structure and function
True
The reaction for photosynthesis
6CO2 + 6H20 + (energy) → C6H12O6 + 6O2
Draw out the reaction for the formation of ammonia (NH3)
N2 + 3H2 ===> 2NH3
The most strong bonds in organisms
Covalent bonds
These type of bonds occur between water molecules and ammonia molecules
hydrogen bonds
___ ___ ____ forces are driven by induced electrical interactions between two or more atoms or molecules that are very close to each other. Van der Waals interaction is the weakest of all intermolecular attractions between molecules.
Van der Waals forces (LDF)
Chemical reactions make and break chemical bond
True
What is the chemical reaction for the formation of ammonia affected by?
reactant concentration
The molecule (compound) CH4 is a pyramid, or a completed _____, because all four hybrid orbitals of the carbon atom are shared with hydrogen atoms
tetrahedron
The chemical reaction for the formation of ammonia is affected by…
reactant concentration
Chemical reactions make and break chemical bonds
True
Chemical equilibrium is a ____ equilibrium
dynamic
Does a chemical equilibrium mean that reactants and products are equal in concentration?
No
T/F Chemical equilibrium has a net effect on the concentrations of reactants and products
False
T/F The concentrations of reactants and products are stabilized at a particular ratio
True
