Element Classes and Ions

Ions and Element Classes

Metals, Nonmetals and the struggle for atomic stability

But first... a refreshing set of review questions

Have your Periodic Tables Ready...

Multiple Choice

What is the electron configuration of an atom of Calcium? (Ca)

Hint: In column 2

• 2-8

• 2-8-2

• 2-8-8-2

• 2-8-8

Multiple Choice

Where are the valence electrons of an atom found?

• in a core energy level

• in the nucleus

• in the outermost occupied energy level

Multiple Choice

Since neutral Ca atoms have configuration 2-8-8-2 , how many valence electrons do they have?

• 8

• 2

• 20

• 40

Multiple Choice

What is the Octet Rule?

• All atoms must have 8 electrons

• Most atoms react until they have 8 valence electrons

Multiple Choice

Since Ca atoms have configuration 2-8-8-2 and follow the octet rule, which is likely to happen?

• loss of 2 electrons from 4th energy level

• gain of 6 electrons to 4th energy level

Multiple Choice

What will be the charge of a calcium ion when it loses its 2 electrons from 4th energy level?

• -2

• 0

• +2

Calcium atom becomes calcium ion

• atom 2-8-8-2

• ion 2-8-8

• atom was neutral (20 p⁺ and 20 e^-)

• ion is not neutral  $20\ p^{+\ }\ne\ ^{ }18\ e^-$  

• 2 more protons than electrons = net 2+

• Ca 2+ ion is a Cation

2 General types of ions

• Cation: positively-charged ion

• Metallic elements form cations (Na⁺, Fe³⁺, Mg²⁺)

• Anion: negatively-charged ion

• Nonmetallic elements form anions (O^2- , Br^-)

Which elements are metallic?

and which are nonmetallic?

Find the Bolded "Staircase" line.

Elements to the left are Metals. (red)

• Ex: Na, Ca, Fe, Ag, Co, Ti, etc.

  (Except hydrogen, H)

• Metals lose e^-, forming positive ions (cations)

Find the Bolded "Staircase" line.

Elements to the right are nonmetals. (+ H)

• Ex: O , P, Cl, Br, Se

• Nonmetals gain e^-, forming negative ions (anions)

Multiple Choice

The element nitrogen (N) would be considered a...

(Hint: N is located in the 2nd row)

• metal

• nonmetal

Multiple Choice

Nitrogen would form a(n)

• cation

• anion

Multiple Choice

The element potassium (K) would be considered a...

(hint: K is located in the far left column)

• metal

• nonmetal

Multiple Choice

Potassium (K) would form a(n)

• cation

• anion

Multiple Choice

The element cobalt (Co) would be considered a...

(it is in the upper middle of the table)

• metal

• nonmetal

Noble Gases

• Nonmetals in Column 18

• Do NOT form ions

• inert (unreactive)

• naturally possess a valence octet (-He)

• Ex: Argon 2-8-8

• Monoatomic ions have e^-configurations that are isoelectronic to the e^- configuration of a noble gas atom

Multiple Choice

When sulfur reacts with a metal element, it gains 2 e^- to become a S^2- anion called sulfide. Its configuration goes from 2-8-6 to ...

• 2-8-8

• 2-8-4

Multiple Choice

Sulfide anion has configuration 2-8-8, which noble gas is it now isoelectronic to?

• He

• Ne

• Ar

• Kr

Recap

• Positively-charged ions are called cations. Metals form these. Metals are the left of the bolded "staircase" line.

• Negatively-charged ions are called anions. Nonmetals form these. Nonmetals are the right of the bolded "staircase" line.

• Column 18 are the Noble Gases. They do not form ions.

• Isoelectronic means to have matching e^- configurations

The End.

Study the Quizlet Flashcards

or

Move directly to the Google Form "Element Classes and Ions"