MARIA MORA ADROVER
CHEMISTRY SEMESTER 1 FINAL
1. MATTER
SCOPE OF CHEMISTRY
● Chemistry def.: the study of the composition of matter and the changes that matter
undergoes.
○ Affects almost everything we can see and every action that we take
○ Touches every area of our lives
● Matter def.: anything that has mass and takes up space
○ Virtually everything around us is matter, including living and non living things.
● Chemists look at the world in 2 ways:
○ Macroscopic: Things we can see and touch
○ Microscopic: The small particles that make up matter
■ Chemists must observe matter and do experiments macroscopically
and the generalizations and explanations that are microscopic in
nature.
MIXTURE
● Mixture def.: Combination of two or more substances in any proportion
■ The substances in a mixture don’t combine chemically
○ Opposite of compound because they have fixed proportions and compound
chemically.
● A homogeneous mixture has the same composition throughout. Ex: lemonade, salt
water
● A heterogeneous mixture varies in its composition. Ex: cookie dough
● There’s three types of mixtures based on the size of the particles:
Solutions Homogeneous, tiny particles, particles
are too small to see them and to be
filtered out
Colloids Homogeneous, medium-sized particles,
we can see the particles but they cannot
be filtered out
Suspensions Heterogeneous, large particles, you can
see them and also filter them out
● The components of a mixture combine but they retain their physical properties
○ Examples: boiling point, ability to dissolve, particle size…
PHYSICAL CHANGE
● Physical change def.: Change to a sample of matter in which some
properties of the material change but the identity of matter doesn't. Ex:
melting
● Some of them can be reversible and other irreversible
, ○ Reversible: Involve change of state
○ Irreversible: Can’t be undone and doesn't alter the chemical makeup.
PHYSICAL PROPERTIES
● Physical property def.: Characteristics of a substance that can be observed
or measured without changing the identity of the substance.
○ Examples: color, hardness, malleability, solubility, electrical
conductivity, density, melting points, and boiling points.
● Density can be a very useful parameter for identifying an element.
○ Iodine has very low density compared to zinc and gold and platinum
have very high density.
● Hardness helps determine how an element should be used (especially a
metal)
○ Silver and gold are really soft while titanium, tungsten and chromium
are much harder
■ Carbon in graphite is soft and carbon in a diamond is seven
times harder.
PERCENT YIELD ??
It's a lab calculation in quantity.
2. THE PERIODIC TABLE
SMALL REVIEW:
Atomic Number: number of protons & electrons in the atom
Number of Neutrons: Mass of element - atomic number
MENDELEEV’S PERIODIC TABLE
Periodic Table was first built using a set of cards. By:
DMITRI MENDELEEV:
● In 1869 Russian chemist and teacher published
periodic table
, ● Why? Mendeleev was writing a chemistry book for his students and wanted to
make their life easier by organizing all the known elements at that time
according to their chemical properties
○ Organized information for each element and put that information on
note cards so that they could be rearranged when needed
○ Discovered: when placing the elements in order of increasing atomic
mass, certain similarities in chemical behavior repeated themselves
○ Believed: elements with atomic masses of 68 and 70 would eventually
be discovered and that they would fit chemically into spaces with no
chemical symbol in the periodic table.
PERIODIC LAW
● When Mendeleev put out his periodic table we didn’t know anything about the
existence of the nucleus until Rutherford did his gold foil experiment.
● The English physicist Henry Moseley examined x-ray spectra of some
chemical elements
○ He shoot X-rays through the crystals of the element to study the
wavelengths of the radiation he detected
■ He found that there was a relationship between wavelength and
atomic number
● And this led to the discovery that the atomic number was
the number of protons in the nucleus of each atom
○ He realized that the elements on the periodic table
should be arranged in order of increasing atomic
number instead of atomic mass.
● Mendeleev and Moseley are credited with being most responsible for the
modern periodic law
○ Periodic law: when elements are arranged in order of increasing
atomic number, there is periodic repetition on the physical and
chemical properties.
○ Each horizontal row- period. New principal energy level is being filled
○ Each vertical column - group. Elements with similar chemical
properties
MODERN PERIODIC TABLE
● The periodic table of nowadays has undergone many changes since it was
first developed by Mendeleev and Moseley.
○ Many other elements have been discovered and others synthesized.
○ The periodic table is an arrangement of the elements in order of their
atomic numbers
○ Most of the elements have been known since ancient times and have
symbols based on their latin names.
● A period is a horizontal row of the periodic table
CHEMISTRY SEMESTER 1 FINAL
1. MATTER
SCOPE OF CHEMISTRY
● Chemistry def.: the study of the composition of matter and the changes that matter
undergoes.
○ Affects almost everything we can see and every action that we take
○ Touches every area of our lives
● Matter def.: anything that has mass and takes up space
○ Virtually everything around us is matter, including living and non living things.
● Chemists look at the world in 2 ways:
○ Macroscopic: Things we can see and touch
○ Microscopic: The small particles that make up matter
■ Chemists must observe matter and do experiments macroscopically
and the generalizations and explanations that are microscopic in
nature.
MIXTURE
● Mixture def.: Combination of two or more substances in any proportion
■ The substances in a mixture don’t combine chemically
○ Opposite of compound because they have fixed proportions and compound
chemically.
● A homogeneous mixture has the same composition throughout. Ex: lemonade, salt
water
● A heterogeneous mixture varies in its composition. Ex: cookie dough
● There’s three types of mixtures based on the size of the particles:
Solutions Homogeneous, tiny particles, particles
are too small to see them and to be
filtered out
Colloids Homogeneous, medium-sized particles,
we can see the particles but they cannot
be filtered out
Suspensions Heterogeneous, large particles, you can
see them and also filter them out
● The components of a mixture combine but they retain their physical properties
○ Examples: boiling point, ability to dissolve, particle size…
PHYSICAL CHANGE
● Physical change def.: Change to a sample of matter in which some
properties of the material change but the identity of matter doesn't. Ex:
melting
● Some of them can be reversible and other irreversible
, ○ Reversible: Involve change of state
○ Irreversible: Can’t be undone and doesn't alter the chemical makeup.
PHYSICAL PROPERTIES
● Physical property def.: Characteristics of a substance that can be observed
or measured without changing the identity of the substance.
○ Examples: color, hardness, malleability, solubility, electrical
conductivity, density, melting points, and boiling points.
● Density can be a very useful parameter for identifying an element.
○ Iodine has very low density compared to zinc and gold and platinum
have very high density.
● Hardness helps determine how an element should be used (especially a
metal)
○ Silver and gold are really soft while titanium, tungsten and chromium
are much harder
■ Carbon in graphite is soft and carbon in a diamond is seven
times harder.
PERCENT YIELD ??
It's a lab calculation in quantity.
2. THE PERIODIC TABLE
SMALL REVIEW:
Atomic Number: number of protons & electrons in the atom
Number of Neutrons: Mass of element - atomic number
MENDELEEV’S PERIODIC TABLE
Periodic Table was first built using a set of cards. By:
DMITRI MENDELEEV:
● In 1869 Russian chemist and teacher published
periodic table
, ● Why? Mendeleev was writing a chemistry book for his students and wanted to
make their life easier by organizing all the known elements at that time
according to their chemical properties
○ Organized information for each element and put that information on
note cards so that they could be rearranged when needed
○ Discovered: when placing the elements in order of increasing atomic
mass, certain similarities in chemical behavior repeated themselves
○ Believed: elements with atomic masses of 68 and 70 would eventually
be discovered and that they would fit chemically into spaces with no
chemical symbol in the periodic table.
PERIODIC LAW
● When Mendeleev put out his periodic table we didn’t know anything about the
existence of the nucleus until Rutherford did his gold foil experiment.
● The English physicist Henry Moseley examined x-ray spectra of some
chemical elements
○ He shoot X-rays through the crystals of the element to study the
wavelengths of the radiation he detected
■ He found that there was a relationship between wavelength and
atomic number
● And this led to the discovery that the atomic number was
the number of protons in the nucleus of each atom
○ He realized that the elements on the periodic table
should be arranged in order of increasing atomic
number instead of atomic mass.
● Mendeleev and Moseley are credited with being most responsible for the
modern periodic law
○ Periodic law: when elements are arranged in order of increasing
atomic number, there is periodic repetition on the physical and
chemical properties.
○ Each horizontal row- period. New principal energy level is being filled
○ Each vertical column - group. Elements with similar chemical
properties
MODERN PERIODIC TABLE
● The periodic table of nowadays has undergone many changes since it was
first developed by Mendeleev and Moseley.
○ Many other elements have been discovered and others synthesized.
○ The periodic table is an arrangement of the elements in order of their
atomic numbers
○ Most of the elements have been known since ancient times and have
symbols based on their latin names.
● A period is a horizontal row of the periodic table
