_____ 1. A __ is a subatomic particle with a +1 charge.a. neutron b. proton c. electron d. Ion

_____ 2. A __ is a subatomic particle with a -1 charge.a. neutron b. proton c. electron d. Ion

_____ 3. A __ is a subatomic particle without any charge.a. neutron b. proton c. electron d. Ion

_____ 4. A __ is an atom or group of atoms that has a positive or negative charge.

a. compound b. molecule c. ionic compound d. Ion

_____ 5. Which of the subatomic particles is considered to be almost massless?

a. neutron b. proton c. electron d. ion

_____ 6. What is the unit used to measure the mass of subatomic particles?

a. grams b. moles c. kilograms d. AMUs

_____ 7. Changing the number of these particles in an atom will change the identity of the element.

a. neutron b. proton c. electron d. Ion

_____ 8. Changing the number of these particles in an atom will cause the atom to become charged.

a. neutron b. proton c. electron d. Ion

______9. Which of these particles is always located outside of the nucleus?

a. neutron b. proton c. electron d. Ion

_____10. Differences in the numbers of these causes the formation of isotopes.

a. neutron b. proton c. electron d. ion

Lesson 22 Ionic Compounds and Ionic Bonding

Objectives:-         The student will explain why a stable octet is

important.-         The student will describe the basic steps in the

formation of a bond between sodium and chlorine.

-         The student will list the properties of a salt.

-         The student will describe differences between the bonding in salts and metals.  PA Science and Technology Standards: 3.4.10.A; 3.4.12.A

Standard Deviants Tape 1I B The Elements 2:57

I.                    Stabilitya.      Filled energy levels make noble gas atoms stable.

                        i.      Noble gases have filled outer s and p levels.                        ii.      Helium is the only exception – it possesses a full s level, the only level it contains.                        iii.      Eight electrons in their outer levels helps make atoms stable.

b.      The octet rule predicts reactivity of atoms.                        i.      8 electrons in the outermost energy level is called a stable octet.

1.      They don’t form bonds easily.2.      They are less reactive.

                       ii.      Elements with less than 8 electrons in their outer levels are more reactive.                       iii.      They try to form bonds with other atoms to get to 8 electrons in those levels.                       iv.      Octet Rule – main block elements form bonds by rearranging electrons so that each atom has a stable octet in its outermost energy level.                       v.      Transition elements achieve some stability by using d electrons, but the octet rule is the best indicator for the main block elements.

c.      Electron transfers create charged particles.

                       i.      Some atoms give up electrons, and some accept them, in order to follow the octet rule.

                       ii.     This creates an electrical imbalance, because these atoms have more/less electrons than protons.

                       iii.    These positive and negative charges bring the particles together to form ionic bonds –

the kind found in salts.II.                 Electron transfers

a.      Sodium atoms lose electrons to form stable octets.                       i.      After losing an electron, sodium has the same electron configuration as neon, a noble gas.

                       ii.     As a result, sodium becomes electrically charged – it picks up a +1 charge.

iii. Cation – any ion with a positive charge.

b.      Chlorine atoms gain electrons to achieve stable octets.

                i.      After gaining an electron, chlorine has the same electron configuration as argon, a noble gas.

                ii.      As a result, chlorine becomes electrically charged – it picks up a –1 charge.

iii. Anion – any ion with a negative charge.

c.       Oppositely charged ions attract and bond to each other.

     i.      Ionic bond – a bond formed by the attraction of oppositely charged ions.

         ii.      All salts are held together by ionic bonds.

              iii.     The structures of salts show that the attraction between ions is not between only one

ion of each element.

              iv.     They form a tightly packed crystal structure with a distinctive shape.

              v.      Ionic compound – a chemical compound composed of cations and anions combined so that the total positive and negative charges are equal.

                          vi.      Steps in formation of NaCl:

Compounds Virtual Lab 2 video

III.         Explaining the properties of saltsa.       Salts are made of ionsb.      Salts have ordered packing arrangements.c.       Salts do not melt and boil easilyd.      Salts are hard and brittle.

IV.  Contrasting the bonding in salts and metals

a.       Metals have a lattice structure

                 i.      Even though salts contain metal ions, their properties are different from those

of metal atoms bonded together.

                            ii.      Metals have the following properties

1.      They conduct electricity in the solid state2.      They are softer than salts3.      They are more malleable and

ductile than salts.

iii. The crystal structure of a metal has atoms of the same element nearby, and the atoms “share” electrons in a common “electron pool” – they are not attached to specific atoms.

iv.      Because electrons are free to move throughout the metal, it is able to conduct electricity.

v.      Because the electrons can move, the atoms are able to change position somewhat without breaking the attraction between them. This allows them to be pounded or stretched without breaking.

Questions:1. Why is a stable octet important?2. Explain the process that occurs for

sodium and chlorine to form a bond.3. List the four properties of salts

discussed, and explain why each one occurs.

4. Metals have four properties unlike salts. List these four properties, and explain why they, as a group, occur with metals and not with salts.