CH. 11 (REVISED) IPC TEST REVIEW

Name the subatomic particles in an atom

Proton, neutron, electron

How is the periodic table organized?

Rows (periods) and columns (groups)

Polar molecules, such as sugar and water, _________ easily in one another because the attraction of opposite charges

dissolve

polar compounds ______ in polar

dissolve

_____________ covalent bonds are not as strong as triple but stronger than single

double

What is the negative subatomic particle in an atom?

electron

The letters in a chemical formula represent the

element

the letters in a chemical formula represent the ______________

elements

In a carbon dioxide molecule, a double covalent bond forms when the carbon atom shares _______pairs of valence electrons with each oxygen atom

equal- picture:

In a non polar molecules share electrons _______________

equally

What is the atomic number?

is the number of protons in an atom (or electrons)

like dissolves _________

like

covalent conductors have __________ melting and boiling points

low

characteristics of covalent compounds are:

low melting point, low boiling point and poor conductors of electricity and thermal energy

element

made up of one type of atom, but compounds are chemical combinations of different types of atoms.

An element that is a great conductor of electricity and thermal energy.

metal

A semi conductor of electricity and thermal energy.

metalloid

Do electrons have an exact location?

no, electrons are in constant motion around the nucleus

Molecules made up of atoms of the SAME element are ________________ because the atoms are identical

non polar

non-polar can dissolve in _________________

non polar

an example of a non-polar

oil

In a ____________________ covalent bond, three pairs of valence electrons are shared between 2 atoms

one triple- picture

In a molecule of water, the ________ atom attracts the electrons more strongly than each hydrogen atom

oxgen

Because the electrons have a slightly negative charge, there is a slight negative charge near the ______ atom, there is a slight ______ charge near the hydrogen atom.

oxygen, positive

In a hydrogen molecule a ______ covalent bond forms when each atom shares its valence electrons with the other

polar- picture:

covalent conductors are _________ conductors of electricity and thermal energy.

poor

compounds and the elements that form them often have very different chemical and physical __________________

properties

In a covalent bond, one atom can attract the shared electrons more _______ than the other atom can

strongly

the number in a chemical formula represent

the number of atoms of that element used in the compound

How do you know how many bonds an atom can form using the electron dot diagram?

the number of unpaired dots

Polar O/h/h shows

the shared electrons are pulled closer to the oxygen atom than the hydrogen atom

_______ covalent bonds are strongest

triple

Which part of an atom participates in chemical bonding?

valence electron

atoms can bond to form compounds by sharing ___________________________________________.

valence electrons

What is a valence electron?

an outermost electron of an atom that participates in chemical bonding

A force that holds atoms together is called ________.

Chemical bond

Chemical Bonds

Chemical bonds join atoms together. It is a force that holds atoms together in a compound.

How many valence electrons do elements in Group 17 have?

7

How many valence electrons must be present for an atom to be stable?

8

What is the maximum number of electrons in the second energy field?

8

How many bonds can chemically stable atoms form?

0

What is the maximum number of electrons in the first energy field?

2

When you look at the chemical formula CO2 it tells you:

2 atoms of oxygen combined with one atom of carbon

ball and stick formula

3 balls representing the elements with stick lines connecting them

The Periodic Table

A library about all chemical elements; Each block on the periodic table includes basic properties of each element such as the element's state of matter at room temperature and its atomic number(number of protons in each atom of the element). Each block also lists an element's atomic mass, or the average mass of all the different isotopes of that element.

Energy Levels

Areas of space in which electrons move around the nucleus are called ______ _______. Electrons closest to the nucleus have the least amount of energy. They are in the lowest energy level. Electrons farthest from the nucleus have the greatest amount of energy. They are in the highest energy level.

Determining an Ion's Charge

Atoms are electrically neutral because they have the same number of proton and neutrons. Once an atom gains or loses electrons , it becomes a charged atom.

What is a compound molecule?

Atoms of different elements are combined.

Noble Gases

Chemically Stable and do not react easily, or form bonds. All the dots are paired for group 18. STABLE AND EACH HAVE 8 Valence Electrons with the exception of Helium(2 Valence Electrons). Atoms tend to gain/lose(ionic bond), or share(covalent bond) valence electrons until each atom has the same number of valence electrons as the NOBLE GASES. Stable atoms have 4 pairs of valence electrons.

Comparing Ionic and Covalent Compounds

Covalent- two or more nonmetal atoms that share electrons and form a unit(molecule) Covalent compounds, such as water, are made up of many molecules. However, when nonmetal ions bond to metal ions in an ionic compound, there are no molecules. Instead, there is a large collection of oppositely charged ions. All of the ions attract each other and are held together by ionic bonds.

Electrons

Different electrons in an atom have different amounts of energy. An electron moves around the nucleus at a distance that corresponds to its amount of energy.

Losing Valence Electrons

EX: When a sodium atom loses one electron then it has ten total electrons which are Neon, a noble gas with a perfect 8 valence electrons.

Electron Number and Arrangement

Each proton has a positive charge; each neutron has no charge, and each electron has a negative charge. In a neutral(uncharged) atom, the number of protons equals the number of electrons. The exact position of electrons cannot be determined. This is because electrons are in constant motion around the nucleus. However, each electron is usually in a certain area of space around the nucleus. Some are in areas close to the nucleus, and some are in areas farther away.

Periods and Groups

Elements are organized in periods(rows) and groups(columns). The periodic table lists elements in order of atomic number. The atomic number increases from left to right across a period. Elements in each group have similar chemical properties and react with other elements in similar ways. An element's position on the periodic table can be used to predict its properties.

Atoms Bond

In nature, pure elements are rare. Instead, atoms of different elements chemically combine and form compounds. Electrons are the atomic PARTICLES that participate in chemical bonding.

Electron Dot Diagram

Made in 1916 by an American Chemist named Gilbert Lewis. He developed a method to show an element's chemical symbol. Helps you predict how an atom will bond with other atoms. The number of unpaired dots is often the number of bonds an atom can form. Atoms with 8 valence electrons are stable.(noble gases) Anything else is unstable. AN electron dot diagram is a model that represents valence electrons in an atom as dots around the element's chemical symbol. The number of UNPAIRED dots in the electron dot diagram tells you how many bonds an atom can form. Many atoms are stable with 8 valence electrons. An atom with at least one UNPAIRED electron is unstable. Unstable atoms can become stable only by forming chemical bonds with other atoms.

Metallic Bonds--- Electron Pooling

Metal atoms typically lose valence electrons when forming compounds. Metal atoms form compounds with one another by combining, or pooling, their valence electrons. A metallic bond is a bond formed when many metal atoms share their pooled valence electrons. The pooling of valence electrons is showed in Aluminum(pg.401) The aluminum atoms lose their valence electrons and become positive ions, indicated by the plus signs. The negative signs indicate the valence electrons, which move from ion to ion. Valence electrons in metals are not bonded to one atom. Instead, a "sea of electrons" surrounds the positive ions.

Metallic Bonds

Metal ion+metal ion Properties: usually solid at room temp. high melting and boiling pts.; do not dissolve in water; good conductors of thermal energy and electricity.; shiny surface; and malleable(hammered into sheets) and ductile(pulled into wires). "pooled electrons" Electrons move freely among atoms. "sea of electrons"

Properties of Metallic Compounds

Metals are good conductors of thermal energy and electricity. Because the valence electrons can move from ion to ion, they can easily conduct an electric charge. When a metal is hammered into a sheet(malleability) or drawn into a wire(ductility), it does not break. The metal ions can slide past one another in the electron sea and move to new positions. Metals are shiny because the valence electrons at the surface of a metal interact with light.

Name the 3 regions on the period table.

Metals, metalloids, non-metals

Electrons and Bonding

Negatively charged electrons have a similar reaction to the positively charged nucleus of an atom. The electrons in energy levels closest to the nucleus of the same atom have a strong ATTRACTION to that nucleus. However, electrons farther from that nucleus are weakly attracted to it. These outermost electrons can be easily attracted to the nucleus of other atoms. This attraction between the positive nucleus of one atom and the negative electrons of another is what causes a chemical bond. THE OUTERMOST ELECTRONS IN AN ATOM ARE INVOLVED IN CHEMICAL BONDING. These electrons are less strongly attached to the nucleus.

Which elements on the period table are the most stable?

Noble gases

Gaining Valence Electrons

NonMetal Atoms can share(covalent) valence electrons with other nonmetal atoms. Nonmetal atoms can also gain valence electrons from metal atoms(ionic). Either way, they achieve the electron arrangement of a noble gas.

Ionic Bond

Nonmetal+metal Properties: solid crystals; high melting and boiling; dissolves in water, solids are poor conductors of electricity and thermal energy; ionic compounds in water solutions conduct electricity. TRANSFERRED electrons; electrically charged but stable atoms.

Most of these are gases at room temperature.

Nonmetals

What is the central part of an atom that contains both protons and neutrons?

Nucleus

structural formula

O=C=O

space filling model

OOO

Understanding Ions

The atoms of 2 or more nonmetals form compounds by sharing valence electrons(covalent). However, when a metal and nonmetal bond, they don't share valence electrons(ionic). Instead, one or more valence electrons transfer from the metal atom to the nonmetal atom. After electrons transfer, the atoms bond, and form a chemically stable compound. Transferring Valence electrons in atoms with the same number of valence electrons as a noble gas.

Ionic compounds

They are usually solid and brittle at room temperature. They also have relatively high melting and boiling points. Many ________ ___________ dissolve in water. Water that contains dissolved ______ __________ is a good conductor of electricity. This is because an electrical charge can pass from ion to ion in the solution.

Ionic Bonds- Electronic Transferring

Typically, metal atoms lose valence electrons and nonmetal atoms gain valence electrons. When forming a chemical bond, the nonmetal atoms gain the electrons lost by the metal atoms. When a metal loses a valence electron it is positive. When the nonmetal gains a valence electron, it is negative. These ions attract each other and form a stable ionic compound. The attraction between positively and negatively charged ions in an ionic compound is an ionic bond.

__________ are located far from the nucleus and have the greatest amount of energy.

Valence electrons

Give an example of a compound molecule

Water molecule

Ion

When an atom loses or gains a valence electron, it becomes an ion. An ion is an atom that is no longer electrically neutral because it has lost or gained valence electrons. Because electrons have a negative charge, losing or gaining an electron changes the overall charge of an atom. An atom that loses valence electrons becomes an ion with a positive charge. An atom that gains valence electrons becomes an ion with a negative charge. This is because the number of protons is now less than the number of electrons

Covalent Bond

When unstable, nonmetal atoms bond together, they bond by sharing valence electrons. A covalent bond is a chemical bond formed when two atoms share one or more pairs of valence electrons. The atoms then form a stable covalent chemical compound. Forms Molecules Nonmetal+nonmetal Properties: gas, liquid, solid; low melting and boiling; often not able to dissolve in water; poor conductors of electricity and thermal energy DULL APPEARANCE (SHARED ELECTRON PAIRS) single, double, or triple bonds. Polar and nonpolar.

covalent bond

a chemical bond formed when tow or more atoms share one or more pairs of valence electrons

chemical bond

a force that holds two or more atoms together.

molecule

a group of atoms held together by covalent bonding that acts as an independent unit

chemical formula

a group of chemical symbols and numbers that represent the elements and the numbers of atoms of each element on a compound

What is an electron dot diagram?

a model that represents valence electrons in an atom as dots around the element's chemical symbol

Polar molecule

a molecule that has a slight positive end and a slight negative end because of UNEQUAL sharing of electrons

compound

a substance made up of two or more different elements. Compounds and the elements that make them often have different properties.

Valence Electrons

an outermost electron of an atom that participates in chemical bonding. They have the most energy of all electrons in an atom; since they are the farthest away from nucleus. The number of valence electrons in each atom of an element can help determine the type and the number of bonds can form. Each element in the same group has the same number of valence electrons. To determine how many valence electrons there are in an element, take the ONES PLACE of that element's group. Unpaired valence electrons form chemical bonds with other elements(gain/lose/share).

Do electrons closer to or farther away from the nucleus have more energy?

farther

What is the positive subatomic particle of an atom?

proton

non polar O=C=O shows

pulled equally by carbon and oxygen atoms

when forming water- valence electrons are _________ between oxygen and hydrogen atoms (which are unstable other own) therefore forming covalent bonds to make 3 stable atoms

shared

Dot diagram

shows elements that are being combined with their dots shown combining

____________ covalent bonds are the weakest of the 3 bonds

single