Atoms and The Periodic Atoms and The Periodic Table ReviewTable Review

The smallest unit of an element that still has The smallest unit of an element that still has the properties of that element is called an the properties of that element is called an atomatom..

Atoms are made up of three subatomic Atoms are made up of three subatomic particles: particles:

ProtonsProtons - in the nucleus, positive - in the nucleus, positive

NeutronNeutron – in the nucleus, neutral – in the nucleus, neutral

ElectronsElectrons – orbit the nucleus, – orbit the nucleus, negativenegative

Atoms are identified by the number of Atoms are identified by the number of protonsprotons they have, or they have, or atomic numberatomic number..

Protons and neutrons have a mass of one Protons and neutrons have a mass of one AMU (atomic mass unit).AMU (atomic mass unit).

Electrons are much smaller. Their mass is Electrons are much smaller. Their mass is so small, it is not counted in the atom’s so small, it is not counted in the atom’s total atomic mass.total atomic mass.

The The atomic massatomic mass is determined by is determined by adding adding the number of protons and neutronsthe number of protons and neutrons..

The magnetic attraction between the The magnetic attraction between the positive protons and the negative positive protons and the negative electrons keep the electrons in orbit electrons keep the electrons in orbit around the neucleus.around the neucleus.

Many models of the atom have been made, Many models of the atom have been made, but the most accepted modern model is but the most accepted modern model is The Electron Cloud ModelThe Electron Cloud Model::

An An electron shellelectron shell is a region around the shell is a region around the shell in which electrons are found.in which electrons are found.

The first shell can hold 2 electrons, the The first shell can hold 2 electrons, the second can hold 8, and the third can hold second can hold 8, and the third can hold 18.18.

The electrons in the outer shell are known The electrons in the outer shell are known as the as the valence electronsvalence electrons..

Atoms that have “full” valence electron Atoms that have “full” valence electron shells are stable and less likely to react shells are stable and less likely to react with other atoms.with other atoms.

Other than the first shell, The most stable Other than the first shell, The most stable number of electrons in the valence shell is number of electrons in the valence shell is 8.8.

When atoms share valence electrons they When atoms share valence electrons they form a form a covalent bondcovalent bond..

An atom normally has the same number of An atom normally has the same number of protons as electrons. Atoms that have protons as electrons. Atoms that have more or less electrons that protons are more or less electrons that protons are called called ionsions, which have a positive or , which have a positive or negative electrical charge.negative electrical charge.

Oppositely-charged ions are attracted to Oppositely-charged ions are attracted to each other and form each other and form ionic bondsionic bonds..

1.Which of the following indicates an atom’s 1.Which of the following indicates an atom’s atomic number?atomic number?

A. Number of electron shells in each atomA. Number of electron shells in each atom

B. Number of protons contained in eachB. Number of protons contained in each

atomatom

C. Number of neutrons contained in each C. Number of neutrons contained in each

atomatom

D. Number of nuclei contained in eachD. Number of nuclei contained in each

atomatom

2. What charge does a proton have?2. What charge does a proton have?

A. NegativeA. Negative

B. NeutralB. Neutral

C. AtomC. Atom

D. PositiveD. Positive

3.Which of the following is the mass number 3.Which of the following is the mass number of an element?of an element?

A. Number of protons + neutronsA. Number of protons + neutrons

B. Number of protons + electronsB. Number of protons + electrons

C. Number of neutrons + electronsC. Number of neutrons + electrons

D. Number of protons + neutrons +D. Number of protons + neutrons +

electronselectrons

4.Which model of the atom is currently 4.Which model of the atom is currently accepted as the most accurate?accepted as the most accurate?

A. Bohr ModelA. Bohr Model

B. Lewis ModelB. Lewis Model

C. Electron Cloud ModelC. Electron Cloud Model

D. Einstein ModelD. Einstein Model

5.The atomic mass of number 13, aluminum, 5.The atomic mass of number 13, aluminum, is 26.982. How many neutrons does it is 26.982. How many neutrons does it have?have?

A. 13A. 13

B. 14B. 14

C. 15C. 15

D. 16D. 16

The Periodic TableThe Periodic TableElementsElements are made up of only one type of are made up of only one type of

atom. They are organized on The Periodic atom. They are organized on The Periodic Table in order of their Table in order of their atomic numberatomic number..

MetalsMetals are found to the left of the zig-zag are found to the left of the zig-zag line.line.

MetalloidsMetalloids, which have some of the , which have some of the properties of metals, are found along the properties of metals, are found along the zig-zag line.zig-zag line.

Non-metalsNon-metals are found to the right of the zig- are found to the right of the zig-zag line.zag line.

Columns in The Periodic Table are called Columns in The Periodic Table are called groupsgroups. Each member of a group has the . Each member of a group has the same number of valence electron.same number of valence electron.

Rows are called Rows are called periodsperiods. Each element in a . Each element in a period has the same number of electron period has the same number of electron shells.shells.

The groups are:The groups are:

#1: Alkali Metals#1: Alkali Metals

#2: Alkaline Earth Metals#2: Alkaline Earth Metals

#3-12: Transition Metals#3-12: Transition Metals

#13: Boron Group#13: Boron Group

#14: Carbon Group#14: Carbon Group

#15: Nitrogen Group#15: Nitrogen Group

#16: Oxygen Group#16: Oxygen Group

#17: Halogens#17: Halogens

#18: Nobel Gases#18: Nobel Gases

Group #1 is the Group #1 is the most reactivemost reactive group. It will group. It will react easily with group #17. Group #2 will react easily with group #17. Group #2 will react easily with group # 16.react easily with group # 16.

Metals have certain properties. They are Metals have certain properties. They are malleablemalleable (able to be bent, formed, and (able to be bent, formed, and pounded into thin sheets). Metals can pounded into thin sheets). Metals can tarnish, which is a tarnish, which is a chemical reactionchemical reaction with with oxygen in which a new substance is oxygen in which a new substance is formed. Metal are shiny, poor insulators, formed. Metal are shiny, poor insulators, and good conductors of heat and and good conductors of heat and electricity.electricity.

6.Oxygen, chlorine, and sulfur are located 6.Oxygen, chlorine, and sulfur are located on the same side of The Periodic Table on the same side of The Periodic Table because they are all:because they are all:

A. gasesA. gases

B. metalsB. metals

C. metalloidsC. metalloids

D. nonmetalsD. nonmetals

7.Element X reacts with K to make K7.Element X reacts with K to make K22X. X.

Which of the following is most likely Which of the following is most likely element X?element X?

A. Hydrogen (1 valence electron)A. Hydrogen (1 valence electron)

B. Nitrogen (5 valence electrons)B. Nitrogen (5 valence electrons)

C. Oxygen (6 valence electrons)C. Oxygen (6 valence electrons)

D. Fluorine (7 valence electrons)D. Fluorine (7 valence electrons)

8.What is happening to the 8.What is happening to the number of protons and number of protons and neutrons as the mass neutrons as the mass increases?increases?

Atomic #Atomic # Atomic Atomic MassMass

11 11

1111 2323

2121 4545

3131 7070

4141 9393

A. The protons are increasing faster than the number of neutrons.

B. The protons are decreasing while the neutrons are increasing

C. Neutrons are increasing faster than the protons.

D. Neutrons are decreasing while the protons are increasing.

9.When determining an element’s chemical 9.When determining an element’s chemical properties, the MOST important subatomic properties, the MOST important subatomic part to look at is __________.part to look at is __________.

A. protonsA. protons

B. valence electronsB. valence electrons

C. neutronsC. neutrons

D. positronsD. positrons

10. Which element is a poor conductor of 10. Which element is a poor conductor of heat?heat?

A. FA. F

B. KB. K

C. FeC. Fe

D. AgD. Ag

KEYKEY

1.1. BB

2.2. DD

3.3. AA

4.4. CC

5.5. BB

6.6. DD

7.7. CC

8.8. CC

9.9. BB

10.10. AA