CHEM 121 EXAM 2 2025/2026 QUESTIONS WITH ANSWERS
GRADED A+
✔✔atoms - ✔✔Matter is composed of tiny particles called _____, which combine to form
molecules. These _____ and molecules interact with each other through various forces,
leading to the diverse properties and behaviors of different types of matter.
✔✔Atom - ✔✔Is the smallest particle of an element
✔✔Atoms - ✔✔are the basic building blocks of matter.
✔✔Atoms - ✔✔They are the smallest units of an element that retain the chemical
properties of that element.
✔✔Atoms - ✔✔consist of a central nucleus, which contains positively charged protons
and uncharged neutrons, surrounded by negatively charged electrons orbiting in
specific energy levels or shells.
✔✔pure substance - ✔✔have fixed or definite composition with distinct/fixed properties.
Is either an element of compound
✔✔pure substance - ✔✔It has a uniform and definite composition throughout, meaning
all its particles are identical
✔✔pure substance - ✔✔its particles are identical. have distinct chemical and physical
properties that are characteristic of the specific substance
✔✔pure substances - ✔✔Examples of it include elements such as oxygen, iron, and
gold, as well as compounds like water (H2O) and sugar (sucrose).
✔✔Element - ✔✔is the simplest form of matter/fundamental substances/pure
substances and cannot be further subdivided by ordinary chemical means
✔✔Elements - ✔✔Can be classified as metal, nonmetals metalloids
✔✔Compound - ✔✔is a chemical combination of two or more elements, in definite
proportions. It is either acid, base or salt.
✔✔Compound - ✔✔are substances composed of two or more different elements
chemically combined in fixed proportions.
✔✔metal - ✔✔shiny appearance, malleable (can be hammered into thin sheets) and
ductile (can be drawn into wires) and good conductor of electricity. such as iron and
copper, are typically shiny, conductive, and malleable.
, ✔✔Nonmetal - ✔✔dull appearance, brittle and poor conductor of electricity. such as
oxygen and nitrogen, are usually dull, poor conductors of heat and electricity, and brittle.
✔✔Metalloids - ✔✔has the characteristics of both metal and nonmetal. such as silicon
and arsenic, have properties that are intermediate between metals and non-metals.
✔✔Mixtures - ✔✔are made up of two or more substances in which the basic identity of
each substance is not change.
✔✔Homogeneous Mixture - ✔✔Homogeneous Mixture a mechanical combination of two
or more substances whose components are equally distributed, only one phase is seen.
✔✔Solution - ✔✔is a homogeneous mixture of two or more substances whose
composition ca be varied within definite limits
✔✔Colloid - ✔✔is a homogeneous mixture consisting of large molecules or
ultramicroscopic particles of one substance dispersed though another substance
✔✔Heterogeneous mixture - ✔✔is a combination of two or more substances whose
components are not equally distributed and can be easily separated by mechanical
means, two or more phases are present
✔✔Suspension - ✔✔is a heterogeneous mixture containing solid particles that are
sufficiently large enough for sedimentation
✔✔Filtration - ✔✔This method is used to separate solid particles from a liquid or gas by
passing the mixture through a filter. The filter allows the liquid or gas to pass through
while retaining the solid particles.
✔✔Filtration - ✔✔Example: separation of sand and water, sand and salt, when brewing
coffee using a drip coffee maker, a paper filter is used to separate the coffee grounds
from the liquid coffee.
✔✔Distillation - ✔✔is used to separate a mixture of liquids with different boiling points.
The mixture is heated, and the component with the lower boiling point vaporizes first.
The vapor is then cooled and condensed back into a liquid, resulting in the separation of
the components.
✔✔Evaporation - ✔✔This method is used to separate a soluble solid from a liquid. The
mixture is heated, causing the liquid to evaporate and leaving behind the solid.
GRADED A+
✔✔atoms - ✔✔Matter is composed of tiny particles called _____, which combine to form
molecules. These _____ and molecules interact with each other through various forces,
leading to the diverse properties and behaviors of different types of matter.
✔✔Atom - ✔✔Is the smallest particle of an element
✔✔Atoms - ✔✔are the basic building blocks of matter.
✔✔Atoms - ✔✔They are the smallest units of an element that retain the chemical
properties of that element.
✔✔Atoms - ✔✔consist of a central nucleus, which contains positively charged protons
and uncharged neutrons, surrounded by negatively charged electrons orbiting in
specific energy levels or shells.
✔✔pure substance - ✔✔have fixed or definite composition with distinct/fixed properties.
Is either an element of compound
✔✔pure substance - ✔✔It has a uniform and definite composition throughout, meaning
all its particles are identical
✔✔pure substance - ✔✔its particles are identical. have distinct chemical and physical
properties that are characteristic of the specific substance
✔✔pure substances - ✔✔Examples of it include elements such as oxygen, iron, and
gold, as well as compounds like water (H2O) and sugar (sucrose).
✔✔Element - ✔✔is the simplest form of matter/fundamental substances/pure
substances and cannot be further subdivided by ordinary chemical means
✔✔Elements - ✔✔Can be classified as metal, nonmetals metalloids
✔✔Compound - ✔✔is a chemical combination of two or more elements, in definite
proportions. It is either acid, base or salt.
✔✔Compound - ✔✔are substances composed of two or more different elements
chemically combined in fixed proportions.
✔✔metal - ✔✔shiny appearance, malleable (can be hammered into thin sheets) and
ductile (can be drawn into wires) and good conductor of electricity. such as iron and
copper, are typically shiny, conductive, and malleable.
, ✔✔Nonmetal - ✔✔dull appearance, brittle and poor conductor of electricity. such as
oxygen and nitrogen, are usually dull, poor conductors of heat and electricity, and brittle.
✔✔Metalloids - ✔✔has the characteristics of both metal and nonmetal. such as silicon
and arsenic, have properties that are intermediate between metals and non-metals.
✔✔Mixtures - ✔✔are made up of two or more substances in which the basic identity of
each substance is not change.
✔✔Homogeneous Mixture - ✔✔Homogeneous Mixture a mechanical combination of two
or more substances whose components are equally distributed, only one phase is seen.
✔✔Solution - ✔✔is a homogeneous mixture of two or more substances whose
composition ca be varied within definite limits
✔✔Colloid - ✔✔is a homogeneous mixture consisting of large molecules or
ultramicroscopic particles of one substance dispersed though another substance
✔✔Heterogeneous mixture - ✔✔is a combination of two or more substances whose
components are not equally distributed and can be easily separated by mechanical
means, two or more phases are present
✔✔Suspension - ✔✔is a heterogeneous mixture containing solid particles that are
sufficiently large enough for sedimentation
✔✔Filtration - ✔✔This method is used to separate solid particles from a liquid or gas by
passing the mixture through a filter. The filter allows the liquid or gas to pass through
while retaining the solid particles.
✔✔Filtration - ✔✔Example: separation of sand and water, sand and salt, when brewing
coffee using a drip coffee maker, a paper filter is used to separate the coffee grounds
from the liquid coffee.
✔✔Distillation - ✔✔is used to separate a mixture of liquids with different boiling points.
The mixture is heated, and the component with the lower boiling point vaporizes first.
The vapor is then cooled and condensed back into a liquid, resulting in the separation of
the components.
✔✔Evaporation - ✔✔This method is used to separate a soluble solid from a liquid. The
mixture is heated, causing the liquid to evaporate and leaving behind the solid.
