The Elements

1. Which elements were discovered by Humphry Davy, all of which incidentally were isolated by electrolysis?

A. B,Na,K,Mg,Ca,Ba,Cl

B. Li,Na,K,Rb,Cs,

C. B,Na,K,Mg,Ca,Sr,F

D. Be,Mg,Ca,Ba,

2. What century was the most prolific for chemists in search of elements, when a whopping 52 were discovered?.

A. 17th

B. 18th

C. 19th

D. 20th

3. Through fractional distallion of liquid air, William Ramsay was the first to isolate several noble gases. What two noble gases were not discovered by William Ramsay?

A. He, Ne

B. He, Rn

C. Ne,Ar

D. Ne,Rn

4. What property of helium, thallium, samarium, radium, rubidium and cesium was the key to their discovery?

A. density

B. radioactivity

C. spectrum

D. toxicity

5.What element can be used as a catalyst for the dissociation of water in sunlight, as an additive to Ti to prevent corrosion,and as a component of jewelry(mixed with Pt)?

A. Ag, silver

B. Au, gold

C. Rh, rhodium

D. Ru, ruthenium

6.Which of the following elements are derived mainly from monazite sands?. 1

A. La,Ce,Pr,Nd,Sm

B. Eu,Gd,Tb,Dy,Ho

C. Tm,Yb,Lu,Th

D. all of the above

7.Which of the following elements is NOT named after a geographical location?.

A. scandium,Sc

B. gallium, Ga,

C. cerium, Ce

D. hafnium,Hf

8. Iodine was discovered by observing a purple colour from a certain reaction. What did its discoverer, Bernard Courtois, react?.

A. Chloride and ashes of kelp.

B. Fluoride and sea water.

C. Sulfuric acid and ashes of kelp.

D. KI and fluoride

9. How many elements are named after objects in our solar system? 2

A. 9

B. 8

C. 7

D. 6

10. What element's free radicals attack ozone in the stratosphere?

A. carbon

B. chlorine

C. iodine

D. cobalt

Explanatory notes to solutions