ACS Exam in General Chemistry
covering CHEM 201/202 Questions
Fully Solved.
Atomic number (Z) - Answer -number of protons that an atom has in nucleus
-unique to each type of element
-element is substance whose atoms all contain identical number of protons
- Z= # protons
Isotope (definition) - Answer -atoms of same element with different masses
-same number of protons, different number of neutrons
Isotope mass number (A) - Answer - A= (#protons)+(#neutrons)
- A=Z+N
-for charge neutrality, number of electrons and protons must be equal
Atomic Symbols - Answer -summarize information about subatomic particles
-every isotope is defined by 2 numbers (Z and A)
Isotopes - Answer -most elements are mixtures of 2 or more stable isotopes
-each isotope has slightly different mass
-distinguished by mass number (A); same atomic number, different mass number
Average atomic mass - Answer -calculated by summing the masses of the element's isotopes,
each multiplied by its natural abundance on Earth
Radioactivity - Answer spontaneous decomposition of the nucleus of some isotopes
Common isotopes of hydrogen - Answer -protium (1/1 H)
-deuterium (2/1 H)
-tritium (3/1 H)
Nuclear radiation - Answer radiation emitted from a nucleus during nuclear decomposition
Alpha particle (4/2 He) - Answer -a helium nucleus, contains two protons and two neutrons
, -mass of 4 amu
-atomic number 2
-charge of +2
Beta particle (0/-1 e) - Answer -an electron
-charge of -1
-mass of 0.00055 amu
Positron (0/1 e) - Answer -mass of an electron (0.00055 amu)
-charge of +1
Gamma ray (0/0 Y) - Answer -high energy electromagnetic radiation
-no effective charge or mass
Neutron (1/0 n) - Answer -charge of zero
-mass of 1
Characteristics of radiation - Answer -alpha: paper
-beta: .5 cm lead
-gamma: 10 cm lead
Transmutation - Answer -when one element is converted into another element
-requires a nuclear reaction
Natural radioactivity - Answer -spontaneous decay of the nucleus of some isotopes
Induced radioactivity - Answer -bombardment of an element with a nuclear particle resulting
in a breakdown (decay) of the nucleus
Paramagnetic - Answer -substances that contained unpaired electrons are attracted to a
magnetic field
Diamagnetic - Answer -substances with all paired electrons are not attracted to a magnetic
field
covering CHEM 201/202 Questions
Fully Solved.
Atomic number (Z) - Answer -number of protons that an atom has in nucleus
-unique to each type of element
-element is substance whose atoms all contain identical number of protons
- Z= # protons
Isotope (definition) - Answer -atoms of same element with different masses
-same number of protons, different number of neutrons
Isotope mass number (A) - Answer - A= (#protons)+(#neutrons)
- A=Z+N
-for charge neutrality, number of electrons and protons must be equal
Atomic Symbols - Answer -summarize information about subatomic particles
-every isotope is defined by 2 numbers (Z and A)
Isotopes - Answer -most elements are mixtures of 2 or more stable isotopes
-each isotope has slightly different mass
-distinguished by mass number (A); same atomic number, different mass number
Average atomic mass - Answer -calculated by summing the masses of the element's isotopes,
each multiplied by its natural abundance on Earth
Radioactivity - Answer spontaneous decomposition of the nucleus of some isotopes
Common isotopes of hydrogen - Answer -protium (1/1 H)
-deuterium (2/1 H)
-tritium (3/1 H)
Nuclear radiation - Answer radiation emitted from a nucleus during nuclear decomposition
Alpha particle (4/2 He) - Answer -a helium nucleus, contains two protons and two neutrons
, -mass of 4 amu
-atomic number 2
-charge of +2
Beta particle (0/-1 e) - Answer -an electron
-charge of -1
-mass of 0.00055 amu
Positron (0/1 e) - Answer -mass of an electron (0.00055 amu)
-charge of +1
Gamma ray (0/0 Y) - Answer -high energy electromagnetic radiation
-no effective charge or mass
Neutron (1/0 n) - Answer -charge of zero
-mass of 1
Characteristics of radiation - Answer -alpha: paper
-beta: .5 cm lead
-gamma: 10 cm lead
Transmutation - Answer -when one element is converted into another element
-requires a nuclear reaction
Natural radioactivity - Answer -spontaneous decay of the nucleus of some isotopes
Induced radioactivity - Answer -bombardment of an element with a nuclear particle resulting
in a breakdown (decay) of the nucleus
Paramagnetic - Answer -substances that contained unpaired electrons are attracted to a
magnetic field
Diamagnetic - Answer -substances with all paired electrons are not attracted to a magnetic
field
