What is the difference between covalent bonds and ionicbonds?
Covalent bonds are formed between atoms to form molecules;ionic bonds are formed between atoms to form compounds.
Covalent bonds involve the sharing of pairs of electronsbetween atoms; ionic bonds involve the sharing of single electronsbetween atoms.
Covalent bonds involve the sharing of electrons between atoms;ionic bonds involve the sharing of protons between atoms.
Covalent bonds involve the sharing of electrons between atoms;ionic bonds involve the electrical attraction between atoms.
Atoms whose outer electron shells contain 8 electrons tendto
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form ions in aqueous solutions.
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form hydrogen bonds in aqueous solutions.
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be stable and chemically nonreactive, or inert.
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be both chemically inert and gaseous at roomtemperature.
Orange juice has a pH of 3 and Black coffee has a pH of 5 Thismeans that:
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Orange juice has 100 times more H+ions than Black coffee
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Orange juice is less acidic than Black coffee
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Orange juice has 4 times more H+ions than Black coffee
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Black Coffee has 100 times more H+ions than Orange juice
Nitrogen (N) is much more electronegative than hydrogen (H).Which of the following statements is correct about the atoms inammonia (NH3)?
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The nitrogen atom has a slight positive charge; each hydrogenatom has a slight negative charge.
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Each hydrogen atom has a partial positive charge; the nitrogenatom has a partial negative charge.
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Each hydrogen atom has a slight negative charge; the nitrogenatom has a strong positive charge.
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The nitrogen atom has a strong positive charge; each hydrogenatom has a strong positive charge.
Atomic number is best described as:
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the number of protons in atom
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the number of neutrons in atom
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the number of electrons in the outermost shell of atom
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only A and B
When two atoms are equally electronegative, they will interactto form
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hydrogen bonds.
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van der Waals interactions.
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polar covalent bonds.
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nonpolar covalent bonds.
The atomic number of neon is 10. Therefore, which of thefollowing is most correct about an atom of neon?
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It has an atomic mass of 10 daltons.
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It has 8 electrons in its outer electron shell.
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It is inert.
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It has 8 electrons in its outer electron shell and it isinert.
About 25 of the 92 natural elements are known to be essentialto life. Which four of these 25 elements make up approximately 96%of living matter?
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carbon, sodium, hydrogen, nitrogen
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carbon, oxygen, phosphorus, hydrogen
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carbon, hydrogen, nitrogen, oxygen
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oxygen, hydrogen, calcium, nitrogen
Which of the following is not considered to be a weakmolecular interaction?
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an ionic bond in the presence of water
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a covalent bond
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a van der Waals interaction
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a hydrogen bond
Which statement is NOT true about the pH scale?
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pH has a balanced level of H+and OH-
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Anything below pH 7 is acidic and above pH7 is basic
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The scale indicates the relative concentrations of hydrogenand hydroxyl ions in a solution.
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all given statements are true
A covalent chemical bond is one in which
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outer-shell electrons of two atoms are shared so as tosatisfactorily fill the outer electron shells of both atoms.
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protons and neutrons are shared by two atoms so as to satisfythe requirements of both atoms.
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outer-shell electrons of one atom are transferred to fill theinner electron shell of another atom.
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electrons are removed from one atom and transferred to anotheratom so that the two atoms become oppositely charged.
A covalent bond is likely to be polar when
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one of the atoms sharing electrons is much moreelectronegative than the other atom.
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one of the atoms has absorbed more energy than the otheratom.
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oxygen is one of the two atoms sharing electrons.
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the two atoms sharing electrons are equallyelectronegative.
In what way are elements in the same column of the periodictable the same?
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They have the same number of electron shells.
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They have the same number of electrons in their valenceshell.
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They have the same number of protons.
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They have the same number of neutrons
The nucleus of a nitrogen atom contains 7 neutrons and 7protons. Which of the following is a correct statement concerningnitrogen?
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The nitrogen atom has a mass number of 14 and an atomic massof 7 grams.
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The nitrogen atom has a mass number of approximately 7 daltonsand an atomic mass of 14.
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The nitrogen atom has a mass number of 14 and an atomic number7
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The nitrogen atom has a mass number of approximately 14daltons and an atomic mass of 7.
Knowing just the atomic mass of an element allows inferencesabout which of the following ?
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the number of protons plus neutrons in the element
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the number of neutrons in the element
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the chemical properties of the element
the number of protons in the element
_______have identical molecular formulas but the atoms in eachmolecule are arranged differently?
organic
homomolecules
isomer
isotope
Which statement is NOT true about ionic bonds?
electrons are completely lost or gained in ion formation
one atom acts as an electron donor and another acts as anelectron acceptor
a salt such as NaCl is formed by an ionic reaction
an ion has the same number of electrons as a non-ionic atom ofthe same element
Why is each element unique and different from other elementsin chemical properties
Each element has a unique atomic mass.
Each element has a unique atomic weight.
Each element has a unique number of neutrons in itsnucleus
Each element has a unique number of protons in itsnucleus.
Which of the following explains most specifically theattraction of water molecules to one another?
hydrogen bond
ionic bond
nonpolar covalent bond
polar covalent bond
Which bond or interaction would be difficult to disrupt whencompounds are put into water?
ionic bond
hydrogen bond
van der Waals interaction
covalent bond
What results from an unequal sharing of electrons betweenatoms?
a polar covalent bond
an ionic bond
a hydrogen bond
a nonpolar covalent bond
which of the following molecules contains the most polarcovalent bond?
H2O
H2
CO2
O2
Two atoms appear to have the same mass number. Theseatoms
must have the same number of protons + neutrons.
must have the same atomic number.
must have the same chemical properties.
must have the same number of electrons.
Electrons exist only at fixed levels of potential energy.However, if an atom absorbs sufficient energy, a possible result isthat
an electron may move to an electron shell closer to thenucleus.
an electron may move to an electron shell farther away fromthe nucleus.
the atom would become a positively charged ion, or cation, andbecome a radioactive isotope.
the atom may become a radioactive isotope.
How many electrons are involved in a triple covalentbond?
one
six
three
two
From its atomic number of 15, it is possible to predict thatthe phosphorus atom has
15 neutrons.
15 electrons.
15 protons and 15 electrons.
15 protons.
Atoms of an element react is most related to the
number of electrons in the outermost shell
number of neutrons in the nucleus
number of electrons in the innermost shell
size of the nucleus
