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chapter 2 general biology

chapter 2 general biology
STUDY
PLAY
proton's electrons and neutron's differ primarily in terms of electric________,________with in an atom, and their________,relative to an electron.
charge
location
mass
what type of subatomic particle occurs in each different element in a unique number and is therefore used as an identifier for specific elements?
proton
true or false: an element that contain more neutron than protons has a different atomic number than the same element with equal numbers of protons and neutrons.
false
An atom or ion is most stable when its outer_________ is occupied by its full complement of_______.
shell
electrons
what percentage of the mass of a human is oxygen?
65%
An aqueous solution is one in which the ____is water.
solvent
when NaCl dissolves in water, the partially ____oxygen atoms in water sorround Na+ while water's partially _____hydrogen atoms surround Cl-.
negative
positive
A person weighs 150 lbs on Earth. on the moon:
his/her mass will be the same, but their weight will be different
Matter is composed of particles called _____. Two or more atoms form a molecule.
atoms
atoms
Carbon, with its 6 neutrons and 6 protons, has been assigned an atomic mass of 12 units.Hydrogen has one of______units, or_____ the atomic mass of carbon.
1;1/12
A covalent bond in which the atoms share electrons unequally is a(n)_____covalent bond.
polar
which of the following best applies to the stability of atoms?
The octet rule
An ion is most stable when
its orbitals are occupied by its full complement of electrons
a9n)____bond is formed when two atoms of different electronegativities share electrons.
polar covalent
Wrote the chemical formula for a compound containing one carbon atom and four hydrogen atoms.
CH4
nitrogen has five electrons in its outer shell, so it can bond with _____ other atoms.
3
why are atoms likely to share electrons?
Because they have unfilled outer valence shells?
By mass, the most abundant element in living organisms is
oxygen
order the following elements based on their contribution to human body mass, from the most abundant element to the least abundant element.
1. oxygen
2.carbon
3. hydrogen
4. nitrogen
Atoms seek to fill the_________rule when outer orbitals are note filled; this can accomplished by gaining, losing, or sharing_________.
octet
electrons
which of the following properties are shared by many chemical reactions that occur in cells?
they require energy
they tend toward equilibrium
they require a catalyst
Rutherford hypothesized that if the positive charge of an atom was evenly dispersed throughout the atom, a beam of alpha particles would be deflected by sheet of gold foil because
like charges repel each other
hydrogen bonds are biologically relevant for
1. collective strength when many are present
2. individual weakness when one or very few are present
3 conferring the unique properties of water.
much of the hydrogen and oxygen in a living organism is in the form of the molecule
water
In Ernest Rutherford's experiment, most of the alpha particles passed through gold foil without being deflected. What conclusion is supported by result?
Most of the volume of an atom is empty space.
Salt such as sodium chloride form ____ when the cations and anions form a regular array
crystals
XY is a salt composed of two atoms, X and Y+ and X- atoms, which is the most electronegative?
X
AN atom with a single unpaired electron in its outer shell is known as a free
radical
Van der Waals forces arise when
random electron movement creates short-lived attractions
AN oxygen molecules (o2) contains a double bond, in which a total of _________electrons are shared.
4
When an interaction between molecules involves relatively few hydrogen bonds, it is
weak and reversible
Van der Waals forces are________than hydrogen bonds
weaker
Which of the following are antioxidants
1.vitamin c
2. flavonoids
3. vitamin E
An atom with a single, unpaired electron in its outer shell is considered chemically reactive because
it can react with other molecules to "steal" an electron
when outer orbitals contain between ___
and_______________electrons, the opportunity for covalent bond formation is available.
one
seven
isotopes of the same element differ in their number of
neutrons
6.02x10/23 particles equals on____________of a substance.
mole
A(n) ___________property is not found in one individual, but it can be identified in a collection or complex system.
emergent
which of the following is an important component of vertebrate skeletons
phosphorus
The total number of orbitals occupied by nitrogen's electrons is___________
5
Elements in the same chemical group have the same bonding properties because
they have the same number of valence electrons
In the conversion of methane and oxygen to carbon dioxide and water, carbon dioxide is a (n):
product
In an atom, the s orbitals have a(n) ____ shape, and the P orbitals have a(n)___ shape.
spherical
eight
which best describes the emergent properties of sodium?
elemental sodium differs from salt (nacl) with respect to overall electrical charge
Chemical __________is reached when the rate of the forward direction is equal to the rate of the reverse direction.
equilibrium
Why are atoms likely to share electrons?
Because they have a high electronegativity
A mole of any substance contains the same number of particles as there are
1. atoms in exactly 12g of carbon
2. in Avogadro's number
________electrons enable chemical bonds to form among atoms.
Valence
An atom or ion is most stable when its outer_______________is occupied by its full complement of ___________
1. shell
2. electrons
An element's atomic _______is based on the protons and neutrons is contains, while its atomic_______is based only on the number of protons.
1. mass
2. number
free radical can be beneficial to humans for their
antibiotic properties
The distribution of charges in an atom/molecule is important to the formation of
1. polar covalent bonds
2. Van der waals forces
3. hydrogen bonds
4. ionic bonds
which of the following statements are correct?
1. atoms in polar covalent bonds bear partial positive and negative charge.
2. hydrogen bonds form between atoms with partial positive and negative charges
3. atoms with different electronegativities may form polar covalent bonds.
elements that have same number of valence electrons
form the same number of chemical bonds.
hydrogen bonds are biologically relevant for
1. individual weakness when one or very few are present
2. collective strength when many are present
3. conferring the unique properties of water
which of the following describes different characteristics of subatomic particles?
Mass, location within an atom, and charge
The fundamental unit of matter is the
atom
elements that ave the same number of valence electrons
form the number of chemical bonds
given the importance of water to life on earth, you might expect which two elements to be prominent in living cells
hydrogen and oxygen
chemical reactions require a source of energy but still may require a (n)____.Most chemical reaction proceed toward ________.
catalyst
equilibrium
a pet scan images area of the body that
are actively taking up glucose
if in a chemical reaction there is no longer a change in the concentration of reactants and products, then
equilibrium has been reached chemical reaction may still be occurring
match the energy content of electrons to their respective orbits
1. lowest energy content
2.highest energy content
3. medium energy content
________is derived from the gravitational pull on an object
weight
explain how atomic mass can be used to determine the relative masses of elements
the atomic mass of an element of interest is compared to the atomic mass of the most common type of carbon
carbon share the most similar bonding properties with silicon because
they share the same number of valence electrons
A covalent bond can be considered polar when
the share electrons are closer to the nucleus of the atom with the higher electronegativity
which of the following best applies to the stability of atoms
The octet rule
order the following elements based on the number of atoms in a gram of each. place the element with the most atoms per gram first and the element with fewest atoms per gram last.
1. carbon
2. sodium
3. helium
4. boron
Due to the presence of protons, and atom's ____________has a net positive electrical charge.
nucleus
chemical properties of atoms refer to the way in which they______with each other, while physical properties refer to the subatomic _________that make up an atom
bond
particles
how many types of atoms can be found in a single element
one
which subatomic particles are confined to a small volume within the nucleus of an atom
neutrons
protons
Element are electrically neutral because
there are equal number of protons and electrons in a given atom
order the following elements base on the number of atoms in a gram of each. place the element with the most atoms per gram first and the element with the fewest atoms per gram last.
1.helium
2. boron
3. carbon
4. sodium
Identify caron, hydrogen, oxygen, nitrogen
atoms that are major components of all living organisms.
The compound CH4 is composed of
one carbon atom and four hydrogen atoms
nitrogen has seven electrons. what is the highest level of orbitals its electrons will fill?
2p