1
BS 161 EXAM 2 NEWEST WITH ACTUAL
QUESTIONS AND CORRECT VERIFIED
ANSWERS|ALREADY GRADED A+/100%
GUARANTEED TO PASS CONCEPTS
Bonds and Forces Review - (answers)
the number of electrons determine how a cell will interact - (answers)-
chemical reactions involve changes in the distribution of electrons between
atoms
- location of electrons in an atom are described by orbitals
+ orbital- the region where an electron is found at least 90% of the time
+ orbitals have common shapes and orientations
+ orbitals are filled in a specific sequence
- orbitals occur in a series called electron shells or energy levels
+ first shell- one orbital- s orbital
+ second shell- one s and three p orbitals (holds 8 electrons)
+ additional shells: four orbitals (8 electrons)
where are reactive electrons in unpaired electrons? - (answers)in their outer
shell
covalent bonds - (answers)- 50-110 kcal/mol
- atoms share one or more pairs of electrons so that outer shells are filled
- covalent bonds are very strong and a lot of energy is required to break them
- biological molecules are held together by covalent bonds and are very strong
- if two atoms have similar electronegativity, they will share valence electrons
equally- non-polar covalent
, 2
- if one atom has more electronegativity, the electrons are drawn to that
nucleus. electrons are not shared equally- polar covalent bond
- if electrons are not shared equally, the atoms will carry partial charges (the
more electronegative atoms will carry are partial negative, and the less
electronegative atom will carry a partial negative)kcal
ions - (answers)- 3-7 kcal/mol
- electrically charged particles- when atoms gain or lose an electron
- cations- positive- lost an electron
- anions- negative- gained an electron
- ionic interactions (ionic bonds)- formed by the electrical attraction between
positive and negative ions
- salts- compounds formed by ionic interactions
hydrogen bonds - (answers)- 3-7 kcal/mol
- an attractive bond formed between the partial positive end of one molecule
and the partial negative end of another
- hydrogen bonds form between polar molecules, and. are important in the
structure of DNA and protein
- polar molecules that form hydrogen bonds with water are hydrophilic
- nonpolar molecules such as hydrocarbons that interact with each other but
not water molecules are hydrophobic
- LDFs- attraction between nonpolar molecules that occur as a result of random
electron movement and distribution. individual reactions are brief and weak,
but over a large molecule can have a significant effect
LDFs - (answers)- 1kcal/mol
- attractions between nonpolar molecules
- result from variations in electron distribution
, 3
- individual interactions are brief and weak
- summed over a large molecule can be substantial
hydrogen clustering - (answers)- 1-2kcal/mol
- interaction between the partial positive charge of a hydrogen, and the partial
negative of another more electronegative atom
- formed in polar molecules
- important for the structure of DNA and protein
- polar molecules that form hydrogen bonds are hydrophilic
- nonpolar molecules such as hydrocarbons that interact with each other, but
not surrounding water molecules are hydrophobic
chemical reactions - (answers)- atoms form bond or change bonding partners
- in all chemical reactions, energy is neither created or destroyed
- energy- the capacity to do work or create change
- energy usually changes form during chemical reactions
list the three properties of water and explain why these properties are
conducive to life
1. hydrogen bonds - (answers)- the polarity of water results in hydrogen
bonding
- because water is more electronegative than hydrogen, water molecules are
polar
- the slightly negative regions of water molecules are attracted to the slightly
positive regions of nearby water molecules
- water molecules can form up to four hydrogen bonds with neighboring
molecules
- when water is in its liquid form, hydrogen bonds are fragile and about 1/20 as
strong as a covalent bond
, 4
- hydrogen bonds form, break, and reform with fast frequency
2. organisms depend on the cohesion of water molecules - (answers)-
collectively, hydrogen bonds hold water together, which is the concept of
cohesion
- cohesion allows for water and nutrients to be transported against
gravitational pulls in plants
-
3. water is the solvent of life - (answers)- a liquid that is a homogeneous
mixture of two or more substances is called a solution
- ex. sugar cube dissolving in a glass of water
- the dissolving agent is the solvent, but the substance that is dissolved into is
the solute
- water is solvent, sugar is solute
- in an aqueous solution, water is the solvent
- water is a common solvent because of its polarity
- even large molecules like proteins can dissolve in water if they have
polar/ionic regions
hydrophilic - (answers)- water loving
- common among ionic or polar bonds
hydrophobic - (answers)- water fearing
- nonionic, nonpolar covalent bonds
how does carbon's electron configuration explain its ability to form large,
complex, diverse organic molecules? - (answers)- carbon is the backbone of
organic molecules
BS 161 EXAM 2 NEWEST WITH ACTUAL
QUESTIONS AND CORRECT VERIFIED
ANSWERS|ALREADY GRADED A+/100%
GUARANTEED TO PASS CONCEPTS
Bonds and Forces Review - (answers)
the number of electrons determine how a cell will interact - (answers)-
chemical reactions involve changes in the distribution of electrons between
atoms
- location of electrons in an atom are described by orbitals
+ orbital- the region where an electron is found at least 90% of the time
+ orbitals have common shapes and orientations
+ orbitals are filled in a specific sequence
- orbitals occur in a series called electron shells or energy levels
+ first shell- one orbital- s orbital
+ second shell- one s and three p orbitals (holds 8 electrons)
+ additional shells: four orbitals (8 electrons)
where are reactive electrons in unpaired electrons? - (answers)in their outer
shell
covalent bonds - (answers)- 50-110 kcal/mol
- atoms share one or more pairs of electrons so that outer shells are filled
- covalent bonds are very strong and a lot of energy is required to break them
- biological molecules are held together by covalent bonds and are very strong
- if two atoms have similar electronegativity, they will share valence electrons
equally- non-polar covalent
, 2
- if one atom has more electronegativity, the electrons are drawn to that
nucleus. electrons are not shared equally- polar covalent bond
- if electrons are not shared equally, the atoms will carry partial charges (the
more electronegative atoms will carry are partial negative, and the less
electronegative atom will carry a partial negative)kcal
ions - (answers)- 3-7 kcal/mol
- electrically charged particles- when atoms gain or lose an electron
- cations- positive- lost an electron
- anions- negative- gained an electron
- ionic interactions (ionic bonds)- formed by the electrical attraction between
positive and negative ions
- salts- compounds formed by ionic interactions
hydrogen bonds - (answers)- 3-7 kcal/mol
- an attractive bond formed between the partial positive end of one molecule
and the partial negative end of another
- hydrogen bonds form between polar molecules, and. are important in the
structure of DNA and protein
- polar molecules that form hydrogen bonds with water are hydrophilic
- nonpolar molecules such as hydrocarbons that interact with each other but
not water molecules are hydrophobic
- LDFs- attraction between nonpolar molecules that occur as a result of random
electron movement and distribution. individual reactions are brief and weak,
but over a large molecule can have a significant effect
LDFs - (answers)- 1kcal/mol
- attractions between nonpolar molecules
- result from variations in electron distribution
, 3
- individual interactions are brief and weak
- summed over a large molecule can be substantial
hydrogen clustering - (answers)- 1-2kcal/mol
- interaction between the partial positive charge of a hydrogen, and the partial
negative of another more electronegative atom
- formed in polar molecules
- important for the structure of DNA and protein
- polar molecules that form hydrogen bonds are hydrophilic
- nonpolar molecules such as hydrocarbons that interact with each other, but
not surrounding water molecules are hydrophobic
chemical reactions - (answers)- atoms form bond or change bonding partners
- in all chemical reactions, energy is neither created or destroyed
- energy- the capacity to do work or create change
- energy usually changes form during chemical reactions
list the three properties of water and explain why these properties are
conducive to life
1. hydrogen bonds - (answers)- the polarity of water results in hydrogen
bonding
- because water is more electronegative than hydrogen, water molecules are
polar
- the slightly negative regions of water molecules are attracted to the slightly
positive regions of nearby water molecules
- water molecules can form up to four hydrogen bonds with neighboring
molecules
- when water is in its liquid form, hydrogen bonds are fragile and about 1/20 as
strong as a covalent bond
, 4
- hydrogen bonds form, break, and reform with fast frequency
2. organisms depend on the cohesion of water molecules - (answers)-
collectively, hydrogen bonds hold water together, which is the concept of
cohesion
- cohesion allows for water and nutrients to be transported against
gravitational pulls in plants
-
3. water is the solvent of life - (answers)- a liquid that is a homogeneous
mixture of two or more substances is called a solution
- ex. sugar cube dissolving in a glass of water
- the dissolving agent is the solvent, but the substance that is dissolved into is
the solute
- water is solvent, sugar is solute
- in an aqueous solution, water is the solvent
- water is a common solvent because of its polarity
- even large molecules like proteins can dissolve in water if they have
polar/ionic regions
hydrophilic - (answers)- water loving
- common among ionic or polar bonds
hydrophobic - (answers)- water fearing
- nonionic, nonpolar covalent bonds
how does carbon's electron configuration explain its ability to form large,
complex, diverse organic molecules? - (answers)- carbon is the backbone of
organic molecules
