NAS2 CHALLENGE UPDATED COMPREHENSIVE QUESTIONS
AND ANSWERS GRADED A+
✔✔electron - ✔✔negatively charged particle, outer shell
✔✔proton - ✔✔positive, in nucleus
✔✔number of protons - ✔✔number of electrons is equal to the same...
✔✔number of protons - ✔✔atomic number is equal to...
✔✔atomic mass - ✔✔sum of protons and neutrons in the nucleus
the weighted average mass of isotopes of an element, found below the element symbol
✔✔ionic bond - ✔✔chemical bond formed between two ions that are opposite charges,
atom gives up one or more electrons to another atom
✔✔covalent bond - ✔✔sharing electron pairs between atoms
✔✔polar covalent bond - ✔✔pair of electrons unequally shared between two atoms
✔✔nonpolar covalent bond - ✔✔two atoms share a pair of electrons with each other
✔✔hydrogen bond - ✔✔weak bond result of attraction between proton and
electronegative atom of another
✔✔enzymes - ✔✔catalyze chemical reactions by lowering activation energy barriers
and converting substrate molecules to products
✔✔substrate - ✔✔reactant acted upon by an enzyme
enzymes active site binds to this
✔✔active site - ✔✔part of an enzyme to which substrates bind and where a reaction is
catalyzed
✔✔enzymes - ✔✔promote chemical reactions by bringing substrates together in an
optimal orientation, thus creating an ideal chemical environment for the reaction to
occur
always return to original state
✔✔decomposition - ✔✔single compound breaks down into two or more elements or
new compounds
, These reactions often involve heat, light, electricity
✔✔synthesis - ✔✔multiple reactants combine to form a single product
Release energy in form of heat and light (exothermic)
Hydrogen and oxygen -> water
✔✔exchange - ✔✔any class of reactions between two substances that involves an
exchange of one or more ionic components (positive and negative charges)
✔✔solvent - ✔✔substance solute is dissolved in
✔✔polar molecule - ✔✔a molecule that has electrically charged areas
covalent bonds - polarity if its atoms differ in electronegativity
can form hydrogen bonds
✔✔nonpolar molecule - ✔✔cannot mix with water
✔✔dissociation - ✔✔leads to acidic and basic conditions
the splitting of a molecule into smaller molecules, atoms, or ions, especially by a
reversible process
✔✔PH - ✔✔measure of acidity
measure of hydrogen ion concentration
✔✔basic/alkaline - ✔✔if pH is above 7 it is...
✔✔acidic - ✔✔if pH is below 7 its...
✔✔diffusion - ✔✔Movement of a substance from an area of high concentration to an
area of low concentration
✔✔dialysis - ✔✔small molecules can diffuse through semipermeable membranes
✔✔osmosis - ✔✔net movement of water through semipermeable membrane
✔✔organic compound - ✔✔any member of large class of gaseous, liquid, or solid
chemical compounds, must contain hydrogen
AND ANSWERS GRADED A+
✔✔electron - ✔✔negatively charged particle, outer shell
✔✔proton - ✔✔positive, in nucleus
✔✔number of protons - ✔✔number of electrons is equal to the same...
✔✔number of protons - ✔✔atomic number is equal to...
✔✔atomic mass - ✔✔sum of protons and neutrons in the nucleus
the weighted average mass of isotopes of an element, found below the element symbol
✔✔ionic bond - ✔✔chemical bond formed between two ions that are opposite charges,
atom gives up one or more electrons to another atom
✔✔covalent bond - ✔✔sharing electron pairs between atoms
✔✔polar covalent bond - ✔✔pair of electrons unequally shared between two atoms
✔✔nonpolar covalent bond - ✔✔two atoms share a pair of electrons with each other
✔✔hydrogen bond - ✔✔weak bond result of attraction between proton and
electronegative atom of another
✔✔enzymes - ✔✔catalyze chemical reactions by lowering activation energy barriers
and converting substrate molecules to products
✔✔substrate - ✔✔reactant acted upon by an enzyme
enzymes active site binds to this
✔✔active site - ✔✔part of an enzyme to which substrates bind and where a reaction is
catalyzed
✔✔enzymes - ✔✔promote chemical reactions by bringing substrates together in an
optimal orientation, thus creating an ideal chemical environment for the reaction to
occur
always return to original state
✔✔decomposition - ✔✔single compound breaks down into two or more elements or
new compounds
, These reactions often involve heat, light, electricity
✔✔synthesis - ✔✔multiple reactants combine to form a single product
Release energy in form of heat and light (exothermic)
Hydrogen and oxygen -> water
✔✔exchange - ✔✔any class of reactions between two substances that involves an
exchange of one or more ionic components (positive and negative charges)
✔✔solvent - ✔✔substance solute is dissolved in
✔✔polar molecule - ✔✔a molecule that has electrically charged areas
covalent bonds - polarity if its atoms differ in electronegativity
can form hydrogen bonds
✔✔nonpolar molecule - ✔✔cannot mix with water
✔✔dissociation - ✔✔leads to acidic and basic conditions
the splitting of a molecule into smaller molecules, atoms, or ions, especially by a
reversible process
✔✔PH - ✔✔measure of acidity
measure of hydrogen ion concentration
✔✔basic/alkaline - ✔✔if pH is above 7 it is...
✔✔acidic - ✔✔if pH is below 7 its...
✔✔diffusion - ✔✔Movement of a substance from an area of high concentration to an
area of low concentration
✔✔dialysis - ✔✔small molecules can diffuse through semipermeable membranes
✔✔osmosis - ✔✔net movement of water through semipermeable membrane
✔✔organic compound - ✔✔any member of large class of gaseous, liquid, or solid
chemical compounds, must contain hydrogen
