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CHEM 1211 GEORGIA SOUTHERN
TEST 1 2026 REAL QUESTIONS WITH
EXPERTLY VERIFIED ANSWERS.
Atomic mass - correct answer -Number or protons and neutrons
in an atom. Usually the decimal number under the Element
Symbol. mass scale on the atomic level is used, where the SI unit
is (amu) or atomic mass unit. -1amu = 1.6605 x 10^-24g
Atomic number
Ex: What is the mass number of an atom with 9 protons, 9
neutrons, and 9 electrons? - correct answer -the number of
protons in the nucleus of an atom, usually the number above the
elements symbol. also known as Z.
Elements of the periodic table are arranged by this.
Example: 18
Isotopes - correct answer -Atoms that are the same element but
have different masses. They have the same number of protons
but a different number of neutrons.
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197Au get protons, neutrons, and electrons. - correct answer -197
is the mass number, that's protons + electron + neutrons. You
need to look at the table and find the atomic number (# of
protons) which is 79. There are also 79 neutrons so, 158-197 =
39 electrons
protons: 79
electrons: 39
neutrons: 79
Ions - correct answer -Atoms can gain or lose electrons to make
partially charged atoms called:
EX: sodium atoms can react to lose an electron, forming a
positively charged sodium cation:
Na →Na++ e-
Oxygen atoms can react to gain electrons, forming a negatively
charged oxide anion:
O + 2e-→O2-
Ion Examples:
F-
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Mg+2
N3- - correct answer -F-
Atomic number is 9 so, Protons: 9
It is negative which means it gained an electron so, Electron: 10
Mg+2
Atomic number is 12 so, Protons: 12
It is positive so it lost electrons so, Electrons: 10
N3-
Atomic number is 7 so, Protons: 7
It is negative bc it added electrons so, Electrons: 10
Atomic Weight - correct answer -an average mass is found by
using all the isotopes of an element weighted by their relative
abundance.
Atomic weight = (istopoe mass) (% abundance)
atomic weight example:
Naturally occurring chlorine is 75.78% 35Cl and 24.22% 37Cl.
Calculate the atomic weight of chlorine. - correct answer -first
change % to decimal so 75.78% = .7578 and 24.22% = .2422
CHEM 1211 GEORGIA SOUTHERN
TEST 1 2026 REAL QUESTIONS WITH
EXPERTLY VERIFIED ANSWERS.
Atomic mass - correct answer -Number or protons and neutrons
in an atom. Usually the decimal number under the Element
Symbol. mass scale on the atomic level is used, where the SI unit
is (amu) or atomic mass unit. -1amu = 1.6605 x 10^-24g
Atomic number
Ex: What is the mass number of an atom with 9 protons, 9
neutrons, and 9 electrons? - correct answer -the number of
protons in the nucleus of an atom, usually the number above the
elements symbol. also known as Z.
Elements of the periodic table are arranged by this.
Example: 18
Isotopes - correct answer -Atoms that are the same element but
have different masses. They have the same number of protons
but a different number of neutrons.
, Page | 2
197Au get protons, neutrons, and electrons. - correct answer -197
is the mass number, that's protons + electron + neutrons. You
need to look at the table and find the atomic number (# of
protons) which is 79. There are also 79 neutrons so, 158-197 =
39 electrons
protons: 79
electrons: 39
neutrons: 79
Ions - correct answer -Atoms can gain or lose electrons to make
partially charged atoms called:
EX: sodium atoms can react to lose an electron, forming a
positively charged sodium cation:
Na →Na++ e-
Oxygen atoms can react to gain electrons, forming a negatively
charged oxide anion:
O + 2e-→O2-
Ion Examples:
F-
, Page | 3
Mg+2
N3- - correct answer -F-
Atomic number is 9 so, Protons: 9
It is negative which means it gained an electron so, Electron: 10
Mg+2
Atomic number is 12 so, Protons: 12
It is positive so it lost electrons so, Electrons: 10
N3-
Atomic number is 7 so, Protons: 7
It is negative bc it added electrons so, Electrons: 10
Atomic Weight - correct answer -an average mass is found by
using all the isotopes of an element weighted by their relative
abundance.
Atomic weight = (istopoe mass) (% abundance)
atomic weight example:
Naturally occurring chlorine is 75.78% 35Cl and 24.22% 37Cl.
Calculate the atomic weight of chlorine. - correct answer -first
change % to decimal so 75.78% = .7578 and 24.22% = .2422
