Aleks Placement Test: Chemistry |
NEWEST EXAM 2026-2027 |
QUESTIONS AND ANSWERS
Matter -ANSWER Anything that has mass and takes up space; made of atoms
Atoms -ANSWER Basic unit of matter which cannot be broken down and contain mostly
empty space; contains three parts: the electron, proton, and neutron
Elements -ANSWER A pure substance that contains only one type of atom
Compound -ANSWER Two or more elements that are chemically bonded; includes ionic
and covalent
Mixture -ANSWER Two or more substances that are together but not bonded
Pure Substance -ANSWER Substance that contains only one kind of compound
Bose-Einstein Condensate -ANSWER The state of matter with the lowest energy;
basically a very cold solid
Solid -ANSWER A state of matter with strong bonds
Liquid -ANSWER A state of matter with weak bonds
Gas -ANSWER A state of matter with no bonds
Plasma -ANSWER The state of matter with the highest energy; it uses ionization instead
of bonds
Robert Boyle -ANSWER First to define an element; any substance is a substance unless
it can be broken down
John Dalton -ANSWER Used and combined previous ideas to discuss the atom;
elements are made of atoms; all atoms of an element are identical; atoms of different
elements are different; law of constant composition; atoms are invisible
Law of Constant Composition -ANSWER Atoms of one element can combine with other
elements to form compounds; a given compound always has the same relative numbers
and types of atoms
J.J. Thomson -ANSWER Discovered electrons and protons and developed the plum
pudding model of an atom
,Electrons -ANSWER The negatively charged particle in an atom; circles around the
nucleus in the electron cloud
Proton -ANSWER The positively charged particle in an atom; located in the nucleus;
determine the element
Neutron -ANSWER The neutral particle in an atom; it has no charge and is located in the
nucleus
Plum Pudding Model -ANSWER A model of the atom that depicts a sphere of positive
charge with electrons scattered throughout
Ernest Rutherford -ANSWER Conducted an experiment in which he shot alpha particles
at gold foil; roved there was a small, dense nucleus with a positive charge and that
protons are positive
Metals -ANSWER Elements located on the left side of the periodic table that want to lose
electrons
Characteristics of Metals -ANSWER - Malleable
- Ductile
- Conductive
- Lustrous
Malleable -ANSWER The ability to be molded into shapes
Ductile -ANSWER The ability to be pulled into wire
Conductive -ANSWER The ability to allow heat or electricity to pass through an object
Lustrous -ANSWER The ability to be shiny
Nonmetals -ANSWER Elements located on the right side of the periodic table that want to
gain electrons
Metalloids -ANSWER Elements placed in a stair-step line between metals and nonmetals;
they have characteristics of both
Diatomic Molecules -ANSWER Elements that occur in pairs in their natural state;
hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine
Electronegativity -ANSWER The ability of a molecule to attract electrons to it; increases
as you move left to right in the table and decreases as you move top to bottom; fluorine
is the hardest
, Atomic Radius -ANSWER The radius of an atom; decreases as you move left to right and
increases as you move top to bottom
Ionization Energy -ANSWER The energy needed to rip off an electron; increases as you
move left to right and decreases as you move top to bottom
Ion -ANSWER An atom that has gained or lost electrons
Anion -ANSWER An atom that gains electrons and has a negative charge; nonmetals
Cation -ANSWER An atom that looses electrons and has a positive charge; metals
Isotope -ANSWER An atom that has changed its number of neutrons
Atomic Number -ANSWER A unique number to each element that tells the number of
protons and the number of electrons if the atom is neutral
Atomic Mass -ANSWER A number that tells the number of protons and neutrons in an
atom
Neutron Number -ANSWER Atomic Mass - Atomic Number
Radioactive -ANSWER A nucleus that spontaneously decomposes, forming a different
nucleus and producing one or more particles; alpha, beta, and gamma ray
Alpha Particle -ANSWER One type of radioactive particle; it is a essentially a helium
nucleus; when this type of particle is released, the mass of the atom is conserved and
so is the atomic number
Beta Particle -ANSWER One type of radioactive particle; it is essentially an electron;
when this type of particle is released, the atomic mass is conserved and the atomic
number gains one (a neutron is changed to a proton)
Gamma Ray -ANSWER One type of radioactive particle; it is a high energy photon of light
and is used to release excess energy; the atom is not changed at all
Half-Life -ANSWER The time required for half of the original sample of nuclei to decay;
each radioactive nucleus of the same element has the same half-life; the shorter the
half-life, the more likely a nucleus will decay
Percent Abundance -ANSWER Elements exist naturally in different isotopes, to the
atomic mass listed on the table is an average
Percent Abundance Equation -ANSWER Average Mass = (%)•(Mass of Isotope A) +
(%)•(Mass of Isotope B) +...
NEWEST EXAM 2026-2027 |
QUESTIONS AND ANSWERS
Matter -ANSWER Anything that has mass and takes up space; made of atoms
Atoms -ANSWER Basic unit of matter which cannot be broken down and contain mostly
empty space; contains three parts: the electron, proton, and neutron
Elements -ANSWER A pure substance that contains only one type of atom
Compound -ANSWER Two or more elements that are chemically bonded; includes ionic
and covalent
Mixture -ANSWER Two or more substances that are together but not bonded
Pure Substance -ANSWER Substance that contains only one kind of compound
Bose-Einstein Condensate -ANSWER The state of matter with the lowest energy;
basically a very cold solid
Solid -ANSWER A state of matter with strong bonds
Liquid -ANSWER A state of matter with weak bonds
Gas -ANSWER A state of matter with no bonds
Plasma -ANSWER The state of matter with the highest energy; it uses ionization instead
of bonds
Robert Boyle -ANSWER First to define an element; any substance is a substance unless
it can be broken down
John Dalton -ANSWER Used and combined previous ideas to discuss the atom;
elements are made of atoms; all atoms of an element are identical; atoms of different
elements are different; law of constant composition; atoms are invisible
Law of Constant Composition -ANSWER Atoms of one element can combine with other
elements to form compounds; a given compound always has the same relative numbers
and types of atoms
J.J. Thomson -ANSWER Discovered electrons and protons and developed the plum
pudding model of an atom
,Electrons -ANSWER The negatively charged particle in an atom; circles around the
nucleus in the electron cloud
Proton -ANSWER The positively charged particle in an atom; located in the nucleus;
determine the element
Neutron -ANSWER The neutral particle in an atom; it has no charge and is located in the
nucleus
Plum Pudding Model -ANSWER A model of the atom that depicts a sphere of positive
charge with electrons scattered throughout
Ernest Rutherford -ANSWER Conducted an experiment in which he shot alpha particles
at gold foil; roved there was a small, dense nucleus with a positive charge and that
protons are positive
Metals -ANSWER Elements located on the left side of the periodic table that want to lose
electrons
Characteristics of Metals -ANSWER - Malleable
- Ductile
- Conductive
- Lustrous
Malleable -ANSWER The ability to be molded into shapes
Ductile -ANSWER The ability to be pulled into wire
Conductive -ANSWER The ability to allow heat or electricity to pass through an object
Lustrous -ANSWER The ability to be shiny
Nonmetals -ANSWER Elements located on the right side of the periodic table that want to
gain electrons
Metalloids -ANSWER Elements placed in a stair-step line between metals and nonmetals;
they have characteristics of both
Diatomic Molecules -ANSWER Elements that occur in pairs in their natural state;
hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine
Electronegativity -ANSWER The ability of a molecule to attract electrons to it; increases
as you move left to right in the table and decreases as you move top to bottom; fluorine
is the hardest
, Atomic Radius -ANSWER The radius of an atom; decreases as you move left to right and
increases as you move top to bottom
Ionization Energy -ANSWER The energy needed to rip off an electron; increases as you
move left to right and decreases as you move top to bottom
Ion -ANSWER An atom that has gained or lost electrons
Anion -ANSWER An atom that gains electrons and has a negative charge; nonmetals
Cation -ANSWER An atom that looses electrons and has a positive charge; metals
Isotope -ANSWER An atom that has changed its number of neutrons
Atomic Number -ANSWER A unique number to each element that tells the number of
protons and the number of electrons if the atom is neutral
Atomic Mass -ANSWER A number that tells the number of protons and neutrons in an
atom
Neutron Number -ANSWER Atomic Mass - Atomic Number
Radioactive -ANSWER A nucleus that spontaneously decomposes, forming a different
nucleus and producing one or more particles; alpha, beta, and gamma ray
Alpha Particle -ANSWER One type of radioactive particle; it is a essentially a helium
nucleus; when this type of particle is released, the mass of the atom is conserved and
so is the atomic number
Beta Particle -ANSWER One type of radioactive particle; it is essentially an electron;
when this type of particle is released, the atomic mass is conserved and the atomic
number gains one (a neutron is changed to a proton)
Gamma Ray -ANSWER One type of radioactive particle; it is a high energy photon of light
and is used to release excess energy; the atom is not changed at all
Half-Life -ANSWER The time required for half of the original sample of nuclei to decay;
each radioactive nucleus of the same element has the same half-life; the shorter the
half-life, the more likely a nucleus will decay
Percent Abundance -ANSWER Elements exist naturally in different isotopes, to the
atomic mass listed on the table is an average
Percent Abundance Equation -ANSWER Average Mass = (%)•(Mass of Isotope A) +
(%)•(Mass of Isotope B) +...
