Go to Section:

• 2–1 The Nature of MatterA. AtomsB. Elements and Isotopes

1. Isotopes2. Radioactive Isotopes

C. Chemical CompoundsD. Chemical Bonds

1. Ionic Bonds2. Covalent Bonds3. Van der Waals Forces

Section 2-1

Section Outline

Go to Section:

Matter –Anything that has mass and occupies space

•1 The basic unit of matter is called the_____.

Go to Section:

Matter –Anything that has mass and occupies space

•1 The basic unit of matter is called the atom.

Go to Section:

Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons

6 electrons6 protons8 neutrons

6 electrons6 protons7 neutrons

Section 2-1

Figure 2-2 Isotopes of Carbon

•2, 3 Atomic ____________ contain _______ and _________.•Protons ___charge size ___ where? _____•Neutrons ___ charge size ____ Where? ___•Electrons ___charge size ____ Where? _____

Go to Section:

Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons

6 electrons6 protons8 neutrons

6 electrons6 protons7 neutrons

Section 2-1

Figure 2-2 Isotopes of Carbon

•2, 3 Atomic Nuclei contain protons and neutrons.•Protons 1+ charge size 1 amu nucleus•Neutrons 0 charge size 1 amu in nucleus•Electrons 1- charge size 1/1840 amu in electron cloud

Go to Section:

4 Atoms are neutral because they contain the same # of _________& protons.

Go to Section:

4 Atoms are neutral because they contain the same # of electrons & protons.

Go to Section:

5 Chemical elements are groups of atoms having the same atomic number, that is, atoms having the same

number__________.

These are all atoms of Carbon. All have atomic #_____.

Go to Section:

5 Chemical elements are groups of atoms having the same atomic number, that is, atoms having the same

number protons.

These are all atoms of Carbon. All have atomic # 6.

Go to Section:

6

C12.011

Section 2-1

An Element in the Periodic Table

•6. Proton # = 6 : shown by the ____________ number• •Also, C atoms have 6 electrons: Since atoms are neutral, if you know proton #, you also know ___________ #!

Go to Section:

6

C12.011

Section 2-1

An Element in the Periodic Table

•6. Proton # = 6 : shown by the atomic number• •Also, C atoms have 6 electrons: Since atoms are neutral, if you know proton #, you also know electron #!

Go to Section:

Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons

6 electrons6 protons8 neutrons

6 electrons6 protons7 neutrons

Section 2-1

Figure 2-2 Isotopes of Carbon

•7 Isotopes are forms of the same element that have the same number of protons but a different number of ______________.

Go to Section:

Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons

6 electrons6 protons8 neutrons

6 electrons6 protons7 neutrons

Section 2-1

Figure 2-2 Isotopes of Carbon

•7 Isotopes are forms of the same element that have the same number of protons but a different number of neutrons.

Go to Section:

Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons

6 electrons6 protons8 neutrons

6 electrons6 protons7 neutrons

Section 2-1

Figure 2-2 Isotopes of Carbon

8 Isotopes are identified by isotopic notation:• Carbon-12, carbon-______, carbon-14 OR• 12C 13C 14C• 6 6 6

Go to Section:

Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14

6 electrons6 protons6 neutrons

6 electrons6 protons8 neutrons

6 electrons6 protons7 neutrons

Section 2-1

Figure 2-2 Isotopes of Carbon

8 Isotopes are identified by isotopic notation:• Carbon-12, carbon-13, carbon-14 OR• 12C 13C 14C• 6 6 6

Go to Section:

9 Isotopes of the same element have the same properties because they have the same atomic number (the same number ___________). For C isotopes, this is ______.

• 12C

13C

14C

• 6 6 6

Go to Section:

9 Isotopes of the same element have the same properties because they have the same atomic number (the same number protons). For C isotopes, this is six protons.

• 12C

13C

14C

• 6 6 6

Go to Section:

10 Chemical compounds are groups of atoms held together by chemical ________. Chemical

compounds are more stable than individual atoms (except for n_______ gas atoms which have stable

---filled—valence electron shells.

•Chemical compounds allow atoms to obey the “_________ rule”. (2 electrons in the outer electron shell in H and He, but 8 for other elements.

Go to Section:

10 Chemical compounds are groups of atoms held together by chemical bonds. Chemical compounds are more stable than individual atoms (except for

noble gas atoms which have stable ---filled—valence electron shells.

•Chemical compounds allow atoms to obey the “octet rule”. (2 electrons in the outer electron shell in H and He, but 8 for other elements.

Go to Section:

11 C_________ f_________ show the numbers of different kinds of atoms bonded together in a single formula unit of

a compound

•NaCl ______ Na ion bonded to one Cl ion•Why do we know it’s composed of ions? Because Na is a _______—an electron donor—and Cl is a __________—an electron acceptor if a metal is present to give it an electron.

Go to Section:

11 Chemical formulas show the numbers of different kinds of atoms bonded together in a single formula unit of a

compound

•NaCl one Na ion bonded to one Cl ion•Why do we know it’s composed of ions? Because Na is a metal—an electron donor—and Cl is a nonmetal—an electron acceptor if a metal is present to give it an electron.

Go to Section:

12 Atoms in compounds are held together by chemical bonds—either i______ or c_______.

Go to Section:

12 Atoms in compounds are held together by chemical bonds—either ionic or covalent.

Go to Section:

Sodium atom (Na) Chlorine atom (Cl)

Sodium ion (Na+) Chloride ion (Cl-)

Transferof electron

Protons +11Electrons -11Charge 0

Protons +17Electrons -17Charge 0

Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding

13 Ionic bonds: attraction of negative ions to positive ions because a metal donates its __________ to a nonmetal atom, forming stable ions with complete _________ shell octets.

Go to Section:

Sodium atom (Na) Chlorine atom (Cl)

Sodium ion (Na+) Chloride ion (Cl-)

Transferof electron

Protons +11Electrons -11Charge 0

Protons +17Electrons -17Charge 0

Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding

13 Ionic bonds: attraction of negative ions to positive ions because a metal donates its electrons to a nonmetal atom, forming stable ions with complete valence shell octets.

Go to Section:

13 _________ bonds form when nonmetal atoms share electrons to fill their valence o_______, linking atoms because both nuclei attract the shared electrons. The dots around the nuclei of each atom represent ___________ __________. The dots in between two nuceli in the formulas are ________________ by the two atoms. The formulas for the c_________ compounds formed below are _____, ______, ______, and ________.

Go to Section:

13 Covalent bonds form when nonmetal atoms share electrons to fill their valence octets, linking atoms because both nuclei attract the shared electrons. The dots around the nuclei of each atom represent valence electrons. The dots in between two nuceli in the formulas are shared by the two atoms. The formulas for the covalent compounds formed below are H2, F2, CO2, and CF4.

Go to Section:

Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)

Transferof electron

Protons +11Electrons -11Charge 0

Protons +17Electrons -17Charge 0

Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding

14 _____are atoms carrying a charge after losing or gaining valence electrons.

Go to Section:

Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)

Transferof electron

Protons +11Electrons -11Charge 0

Protons +17Electrons -17Charge 0

Protons +11Electrons -10Charge +1

Protons +17Electrons -18Charge -1

Section 2-1

Figure 2-3 Ionic Bonding

14 Ions are atoms carrying a charge after losing or gaining valence electrons.

Go to Section:

15. True orFalse. ______Atom that loses electrons becomes a positive ion. (sodium

atoms have 11 protons in the nucleus and 11 neutrons and 11 electrons. Sodium ions have 11

protons, 11 neutrons, and 10 electrons).

Go to Section:

15. True orFalse. True_Atom that loses electrons becomes a positive ion. (sodium

atoms have 11 protons in the nucleus and 11 neutrons and 11 electrons. Sodium ions have 11

protons, 11 neutrons, and 10 electrons).

Go to Section:

15. True orFalse. _________Nonmetal atoms that gain electrons becomes positive ions.

(chlorine atoms have 17 protons in the nucleus and 18 neutrons and 11 electrons. Chlorine ions have 17 protons, 18 neutrons, and 18

electrons).

Go to Section:

15. True orFalse. False_Nonmetal atoms that gain electrons becomes positive ions. (chlorine atoms have 17 protons in the nucleus and 18 neutrons and 11 electrons. Chlorine ions have

17 protons, 18 neutrons, and 18 electrons).

Go to Section:

16 M__________ (Not ionic compounds!) form when atoms are joined with covalent

bonds.

Go to Section:

16 Molecules (Not ionic compounds!) form when atoms are joined with covalent bonds.

Go to Section:

17 _____shared electrons is a single covalent bond. ___ shared electrons is a double covalent bond. _____ shared electrons is a triple covalent bond

A

C•D covalent bonds are formed when atoms share electrons

http://academic.brooklyn.cuny.edu/biology/bio4fv/page/covalent_bonds.html

Go to Section:

17 2_shared electrons is a single covalent bond. 4 shared electrons is a double covalent bond. 6 shared electrons is a triple covalent bond

A

C•D covalent bonds are formed when atoms share electrons

http://academic.brooklyn.cuny.edu/biology/bio4fv/page/covalent_bonds.html

Go to Section:

18 Van Der Waals forces and dipole-dipole interactions hold atoms of nearby molecules together.

•Occasionally, valence electrons are nearer one atom than the other in a covalent bond, creating areas partial charge.

http://www.chem.unsw.edu.au/coursenotes/CHEM1/nonunipass/HainesIMF/images/dipoledipole.jpg