Chemistry - Test #3 (Units 4-5)

Mx. Gwara @Trinity School

GO TO “Chemistry - Substance Quiz” Knowt for Unit 4

GO TO “Chemistry - Substance Quiz” Knowt for Unit 4

OK

UNIT 5: CLASSIFYING COMPOUNDS

OK

READING A PERIODIC TABLE

OK

sides of the table (H-Be; B-He)

representative elements → if ion is formed with this element, it always forms the same charge ion

middle of table (Sc - Zn)

transition metals → if ion is formed with this element, it has variability in ions

bottom of table

rare earth metals

staircase

left = metals; right = nonmetals; close by = metalloids

Al (metal, metalloid, nonmetal?)

Aluminum is a metal, an exception to the staircase.

Right to left charges, rep elements

H column: +1 (H is an exception with +1 -1)

Be column: +2

B column: +3

C column: variability

N column: -3

O column: -2

F column: -1

He column: 0

In the C column (Carbon), what are the charges for Carbon, Silicon and Germanium? (C, Si, Ge?) What about tin and lead (Sn and Pb)?

0; tin and lead have variability…

What are three exceptions to transition metals?

Zinc (Zn); Cadmium (Cd); Silver (Ag)

Charges: +2; +2; +1

Magnesium cation + Chlorine anions = MgCl₂

Cl = -1 … so Mg = +2

Predict the formula between magnesium cations and sulfur anions.

Sulfur is -2 (periodic table)

Magnesium is +2 (last question)

Formula: MgS

The particle diagrams for the compounds in the last few questions should look like molecules. Should they be represented with molecules?

NO. They have charge, thus, they are ions, not molecules!

Predict the formulas for the following compounds:

potassium and oxygen

calcium and selenium

K = +1 ; O = -2; Formula: K₂O

Ca = +2; Se = -2; Formula: CaSe

Would you expect each of the following atoms to gain or lose electrons when forming ions? What ion is the most likely in each case?

Ra 

In 

P 

Te 

Br 

Rb

Ra → +2 → lose

In → +3 → lose

P → -3 → gain

Te → -2 → gain

Br → -1 → gain

Rb → +1 → lose