Tuesday, March 3, 2009

4E5, below is the link to Cheimistry periodic table retest exercise and answers. Those who have not taken the retest because you didn't fail, and needs extra practice, please go try it.

Good luck,
Weiqiang

Fuhua Secondary School
Chemistry Class Re-Test 1
Periodic Table

Name: ………………………………………….. Date: ………………

Class: ………………………………………….. Marks: / 20

Section A (5 marks)

1. Which one of the following gives the number of protons and electrons of an element in Group I of the Periodic Table?

Number of protons, Number of electrons:

A.9,10
B.11,11
C.13,13
D.17,18

2. The symbol of the element rhenium is Re. What is the formula of rhenium(IV) oxide?

A. ReO B. Re2O C. ReO2 D. Re4O

3. An element M forms an ion M-. The electronic configuration of this ion is (2.8). Which statement is true?

A. M is in Group VII and Period 2.
B. M is in Group VII and Period 3.
C. M is in Group VI and Period 2.
D. M is in Group VI and Period 3.

4. What gas is used to fill an electric light bulb to help the wire filament last as long as possible?

A. Air B. Argon C. Carbon dioxide D. Chlorine

5. Fluorine is the first element in Group VII of the Periodic Table. Which statement about fluorine is not correct?

A. It is a gas at room temperature and pressure.
B. It is a more powerful oxidising agent than chlorine.
C. Its molecules are monatomic at room temperature.
D. It forms ionic compounds with metals.

Section B (15 marks)

1. Gallium has the proton(atomic) number 31. It melts at 30°C and boils at 2400°C.

(a) In which Group of the Periodic Table does gallium belong? [1]
(b) (i) Predict the electrical conductivity of gallium at 25°C.
(ii) Give a reason for your answer to (b)(i).
[2]
(c) (i) Would you expect gallium oxide to be basic, acidic or amphoteric?
(ii) Give a reason for your answer to (c)(i).
[3]
(d) Arrange the oxides, Al2O3, B2O3, Ga2O3, In2O3 and Tl2O3 from the most acidic oxide to the most basic oxide.

most acidic most basic
[2]

2. A scientist discovered a new element, Singaponine (with symbol Sa), which is a member of the halogen group of elements and can be placed below astatine in the Periodic Table.

(a) Predict the appearance of Singaponine at room temperature. [1]
(b) How many outer shell electrons are present in an atom of Singaponine? [1]
(c) Predict the formula of the ion formed by Singaponine. [1]
(d) What is the formula of the compound formed between sodium and singaponine?
[1]
(e) (i) Describe and explain what you would expect to see if you pass fluorine
gas into a solution of sodium bromide. [2]
(ii) Write an ionic equation for this reaction. [1]

ANS: Fuhua Secondary School
Chemistry Class Re-Test 1 – Answers
Periodic Table

Section A

1) B 2) C 3) A 4) B 3) C

Section B

1) (a) Gallium belongs to Group III of the Periodic Table.

(b) (i) Gallium is a good electrical conductor at 25°C.

(ii) Gallium is a metal, and metals are good conductor of electricity in the solid state.

(c) (i) Gallium oxide is expected to be an amphoteric oxide.

(ii) Gallium is close to the dividing line between the metals and non-metals, such metals
forms amphoteric oxide. (OR:Gallium is below aluminium in Group III of the
Periodic Table. Since aluminium oxide is amphoteric, gallium oxide should have
similar properties.)

(d) B2O3, Al2O3, Ga2O3, In2O3, Tl2O3

2(a) Black solid.

(b) 7 outer shell electrons.

(c) Sa-

(d) NaSa

(e) (i) The colourless sodium bromide solution will turn orange-brown. Since fluorine is v
more reactive than bromine, fluorine will displace bromine from an aqueous
solution of its ions.

(ii) F2(g) + 2Br-(aq) ® 2F-(aq) + Br2(aq)

FROST

4e5

SNOWMANS

BIRTHS

MEMOIRS

THANKS

Tuesday, March 3, 2009

8:07 PM

FROST

4e5

SNOWMANS

BIRTHS

MEMOIRS

THANKS

Tuesday, March 3, 2009

8:07 PM

8:07 PM