Lecture 4.4a

Which of the following metals commonly occur as salts in the earth's crust?

In what form do Al, Fe, and Sn most commonly occur in the earth's crust?

• As salts

• As oxides

• As sulfides

• As uncombined metals

Which of the following metals are found as sulfides in the earth's crust?

Which metals are found in their uncombined (native) form in the earth's crust?

When metals react, they undergo oxidation. What does oxidation involve?

• A) Gain of electrons

• B) Loss of electrons

• C) Gain of protons

• D) Loss of protons

What happens to the ions of a metal that is easily oxidized?

• A) They are easily reduced to the metal

• B) They are not reduced to the metal

• C) They gain more electrons

• D) They lose more protons

Which of the following is considered when determining the reactivity of a metal?

• A) Its reactions with oxygen

• B) Its reactions with water, acid, and metal displacement reactions

• C) Its reactions with nitrogen

• D) Its reactions with carbon dioxide

Which metal is the most reactive according to the metal activity series?

• A) Calcium (Ca)

• B) Sodium (Na)

• C) Potassium (K)

• D) Magnesium (Mg

Which metal is the least reactive according to the metal activity series?

• A) Gold (Au)

• B) Silver (Ag)

• C) Copper (Cu)

• D) Mercury (Hg)

What is the product when magnesium reacts with acid?

• Mg(OH)₂ and H₂

• Mg²⁺ and H₂

• MgO and H₂O

• MgCl₂ and H₂