Download Chemistry Review Answers

Physics of the Earth CP
Test: 11/20/09
Review for Unit 4 Test: Matter and Chemistry
The Periodic Table- A table arrangement of the elements according to their
atomic numbers so that elements with similar properties are in the same column.
Rows – Horizontal, Left to Right, also known as a period
Columns- Vertical, Up and Down, also known as groups or families
Group Number- The group number is the number assigned to the
vertical columns of the structured list of all known elements in the periodic
table. Elements within the same group have the same number of electrons
in their outer electron shells. Thus, all elements in the same group have
similar chemical properties.
Groups in the Periodic Table- The elements are arranged in the
sequence of their increasing atomic numbers into the periodic table, which
is arranged in rows and columns, so that elements with similar chemical
properties are in the same vertical column.
Families- A group or family is a vertical column in the periodic table.
Groups are considered the most important method of classifying the
elements.
Non Metals- Any of a number of elements, such as oxygen or
sulfur, that lack the physical and chemical properties of metals
Alkali Metals- Any of a group of soft, white, low-density, lowmelting, highly reactive metallic elements, including lithium, sodium,
potassium, rubidium, cesium, and francium.
Alkaline Metals- Any of a group of metallic elements, especially
calcium, strontium, magnesium, and barium, but generally including
beryllium and radium.
Transition Metals- Any of the metallic elements within Groups 3
to 12 in the Periodic Table that have an incomplete inner electron
shell and that serve as transitional links between the most and the
least electropositive in a series of elements.
Metalloids- A nonmetallic element, such as arsenic, that has some
of the chemical properties of a metal. A nonmetallic element, such
as carbon, that can form an alloy with metals.
Halogens- Any of a group of five chemically related nonmetallic
elements including fluorine, chlorine, bromine, iodine, and astatine.
Nobel Gases- Any of the elements in Group O of the periodic
table, including helium, neon, argon, krypton, xenon, and radon.
Other Metals- The 7 elements classified as "other metals" are
located in groups 13, 14, and 15 of the Periodic Table. All of these
elements are solid, have a relatively high density and are opaque.
The "Other Metals" on the Periodic Table are: Aluminum, Gallium,
Indium, Tin , Thallium, Lead, Bismuth
Rare Earth Metals: are located in Group 3 of the Periodic Table
and in the 6th and 7th periods. The Rare Earth Elements are of the
Lanthanide and Actinide series. Most of the elements in the Actinide
series are synthetic or man-made.
Protons, Neutrons, Electrons- sub-atomic particles
Protons- positively charged sun atomic particle
Neutrons- no charge but contributes mass
Electrons- lightest, a stable sub-atomic particle
Charges, MassesCounting subatomic particles in atomsMass Number- add protons and neutrons
Atomic Number- is the number of protons in an atom. The number of
protons is unique for each element. No two elements have the same
atomic number.
Example: Carbon has six protons and an atomic number of 6.
Oxygen has eight protons and an atomic number of 8.
Chemical Symbol- is a one- or two-letter code used to represent an
element. Each element has its own chemical symbol.
Example: C always represents Carbon, Na always represents
Sodium, Fe always represents Iron
Valence Electrons- An electron in an outer shell of an atom that can
participate in forming chemical bonds with other need 8 for stability.
Example: Nobles Gases have all eight and are reluctant to bond
Ions- gain or loss of an electron
Isotopes- different neutrons, atoms of the same element
Chemical Symbols- found on the periodic table, represented by letters or
symbols
Classifying Matter- matter is anything that has mass or volume
Mixture- A composition of two or more substances that are not chemically
combined with each other and are capable of being separated.
Pure Substance- A chemically pure substance is a kind of matter that cannot
be separated into other kinds of matter by any physical or chemical process. It
has the same color, taste, texture and composition at a given temperature
Element- A substance composed of atoms having an identical number of
protons in each nucleus. Elements cannot be reduced to simpler substances by
normal chemical means.
Compound- A pure, homogeneous substance consisting of atoms or ions of two
or more different elements in definite proportions that cannot be separated by
physical means. A compound usually has properties unlike those of its constituent
elements.
Heterogeneous- Consisting of dissimilar elements or parts example:
Homogeneous Mixtures- A composition of two or more substances that are
not chemically combined with each other and are capable of being separated.
Physical vs. Chemical Changes and Properties
Physical Change- A physical change can be changed back to its
original form. A physical change is any change not involving a change in
the substance's chemical identity.
Physical Property- Physical properties are those that can be observed
without changing the identity of the substance. The general properties of
matter such as color, density, hardness, are examples of physical properties.
Example: water can be changed into ice and ice can be changed
back to water, its original form. Or Tearing magnesiaum
Chemical Change- A chemical change cannot be changed back to its
original form. In a chemical change, bonds are broken and new bonds are
formed between different atoms. This breaking and forming of bonds
takes place when particles of the original materials collide with one
another.
Chemical Properties- Properties that describe how a substance changes
into a completely different substance are called chemical properties.
Flammability and corrosion/oxidation resistance are examples of chemical
properties.
Example: wood burning in a fire place.
Bonding- Any of the interactions that account for the association of
atoms into molecules, ions, crystals, metals, and other stable species.
Covalent- Shares electrons- a chemical bond formed by the sharing of
one or more electrons, especially pairs of electrons, between atoms.
Ionic- gives away electrons- one or more electrons are transferred from
one neutral atom (typically a metal)to another (typically a nonmetallic
element
Example: crystals of common salt (sodium chloride, NaCl) are
dissolved in water,
Metallic- sea of electrons- a chemical bond in which electrons are shared
over many nuclei and electronic conduction occurs.
Atomic Structure- The arrangement of the parts of an atom, which
consists of a massive, positively charged nucleus surrounded by a cloud of
electrons arranged in orbits.
Atomic Theory- The physical theory of the structure, properties, and
behavior of the atom
Scientists and Models
Democritus (Solid Spheres)- suggested in 450 BC that the “stuff” that
makes up the world are composed of invisible particles. This theory has
been disproved with the discovery of protons, electrons, neutrons, and even
qwarks!
Dalton (Billiard Ball)- performed many experiments and revised some
of Democritus's ideas. He proposed his own atomic theory in 1803.
 The atoms of a given element are different from those of any
other element; the atoms of different elements can be
distinguished from one another by their respective relative
atomic weights.
 All atoms of a given element are identical.
 Atoms of one element can combine with atoms of other
elements to form chemical compounds; a given compound
always has the same relative numbers of types of atoms.
 Atoms cannot be created, divided into smaller particles, nor
destroyed in the chemical process; a chemical reaction simply
changes the way atoms are grouped together.
 Elements are made of tiny particles called atoms.
Thomson (Plum Pudding)- says that the eletrons are like raisins sitting
in a plum pudding and the pudding is the rest of the atom is like the
pudding. The rest of the atoms is positively charged to neutralized the
negative charge of the electrons.
Rutherford (Nuclear Atomic)- performed the Gold Foil Experiment
and proved there was a positively charged nucleus in an atom surrounded
by electrons but mostly empty space. In 1920 he changed his model to
include protons (positively charged particles.
Bohr (Planetary)- makes electrons look like planets revolving around
the sun. In reality electrons move in different shapes and do not stay on
the same path.
Quantum Mechanical- also known as the Electron Cloud Theory.
Scientists believe electrons fly in specific energy levels or shells around the
nucleus.
Acids and Bases Characteristics
Acids- A substance that yields hydrogen ions when dissolved in water. A
substance that can act as a proton donor. A substance that can accept a
pair of electrons to form a covalent bond.
Bases- A substance that can act as a proton acceptor. A substance that
can donate a pair of electrons to form a covalent bond
ACIDS
BASES
TASTE
SOUR
BITTER
FEEL
STINGS
SLIPPERY
REACTIONS
YES / METAL
CONDUCTS
ELECTROLYTE
RELEASES
H+
NO / METALS
ELECTROLYTE
OH-