PRELESSON FOR NEW RSBI STUDENTS 2009 Part II

31. An ion is an electrically charged particle produced by ….
a. removing electrons from a neutral atom to give a positive ion
b. adding electrons to a neutral atom to give an ion
c. removing electrons from an anion
d. adding electrons to a cation
e. combining cation and anion
32. When an ion is formed, the number of protons ….
a. changes
b. does not change
c. less than the number of neutrons
d. equal to the number of neutrons
e. equal to the number of electrons
33. Neutral atoms can be turned into positively charged ions by removing one or more electrons. A metal is a substance that can form a positive ion. The following possible positive ion is ….
a. Cl+
b. S2+
c. Ca2+
d. F+
e. O+
34. A neutral sodium atom, for example, contains 11 protons and 11 electrons. By removing an electron from this atom will produce ….
a. Na+ ion
b. a negatively charged
c. a positively charged
d. a charge of Na is -1
e. a charge of Na is +2
35. The correct statement about chlorine is….
a. a neutral atom has the same number of ptoton and neutron
b. a neutral chlorine atom contains 7 protons and 7 electrons
c. Cl gains extra electrons become positively charged
d. by adding one more electron we get Cl- ion
e. a net charge of chloride ion is -2
36. The gain or loss of electrons by an atom to form negative or positive ions has an enormous impact on the chemical and physical properties of the atom. The correct example is ….
a. sodium which consists of ions, bursts when it comes in contact with water
b. Na+ and Cl- ions are unreactive, so safely take them into our bodies
c. potassium contains neutral atoms, so it save for us
d. although Cl2 molecules are not neutral, it so reactive
e. whenever we salt our food, it is dangerous for us
37. Democritus (460-370 BC) and somewhat later John Dalton (1766-1844) were the first to consider about matter. The correct statement is ….
a. atom is a wave
b. it is a smallest ion
c. its most macroscopic form
d. an atom is being undivisible
e. atom as being the biggest unit
38. The observation of atom has an important and fundamental consequence. This is ….
a. atomic mass is easily to measure
b. volume of atom equal to its ion
c. volume of atom is could not be observed
d. mass is neither created nor destroyed during a chemical reaction
e. atomic mass is relative because it is determined by the number of protons
39. If atoms are indivisible then they cannot be destroyed during a chemical reaction, so ….
a. the volume of reactants decreases
b. the volume of products increases
c. the mass of reactants will be constant
d. the mass of products less than the mass of reactants
e. the mass of reactants equal the mass of the products
40. In the reaction between hydrogen and oxygen gases, what will be happened?
a. All atoms rearrange themselves but are not destroyed
b. volume before and after reaction is the same
c. volume of hydrogen = volume of oxygen
d. mass of hydrogen = mass of oxygen
e. Mass of reactants changes
41. Mass conservation can be used in chemical calculations. For example iron rust by combining with oxygen to form rust (iron oxide). Suppose 100 g of iron metal rusts. We weigh the rust and find that the rust has a mass of 143 g. What mass of oxygen reacted with the iron?
a. 243 grams
b. 100 grams
c. 143 grams
d. 86 grams
e. 43 grams
42. The modern chemical symbols were introduced by Berzelius. The symbol of sodium and potassium are ….
a. S and P
b. So and Po
c. Na and P
d. Na and K
e. N and K
43. The correct statement about periodic table is ….
a. rows of elements are called columns
b. columns of elements are called groups
c. periods are the vertical columns
d. 1A, 2A 3B etc. are the name of period
e. there are 7 groups in the periodic table
44. There are three general classes of elements distinguished by their physical properties. These are ….
(1) metals, generally shiny and conduct electricity
(2) nonmetals, not shiny, sometimes gasses at STP and poor conductors of electricity
(3) metalloids, properties in between metals and nonmetals
The correct answer is (are) ….
a. (1)
b. (2)
c. (3)
d. (1) and (2)
e. (1), (2), and (3)
45. Some groups of elements in the periodic table have special names. The correct name is ….
a. IA alkali earth metals
b. IB transition nonmetals
c. IIA alkali metals
d. VIIA halogens
e. VIIIA noble metals
46. Elements within a group share similar chemical properties. This is because they have the same ….
a. mass
b. volume
c. number of protons
d. number of neutrons
e. number of valence electrons
47. One of the following metals is an alkali. This is ….
a. sodium
b. calcium
c. barium
d. bromine
e. cromium
48. Alkali and alkali earth metals are ….
a. sodium and lithium
b. potassium and calcium
c. barium and bromine
d. magnesium and chlorine
e. yodine and fluor
49. The following is alkali metals, except ….
a. Na
b. Li
c. K
d. Al
e. Rb
50. From the following metals, alkali earth are ….
a. Li, Na, K, Rb
b. Mg, Ca, Sr, Ba
c. F,Cl, Br, I
d. Na, Mg, Al, Si
e. He, Ne, Ar, Kr
51. The correct properties of metal is ….
a. gas at 25oC
b. low boiling point
c. low melting point
d. solid at room temperature
e. generally solid at room temperature
52. Molecules consist of two or more atoms bonded to one another through "covalent" bonds. The wrong molecular formula is….
a. H2
b. O2
c. O3
d. P6
e. S8
53. The following compound which contains metal is ….
a. acid
b. salt
c. oil
d. air
e. LPG
54. The empirical formula expresses the most simple ratio. The correct molecular and empirical formulas are ….
a. CH4 – CH
b. C4H10 – C2H5
c. H2O – HO
d. C6H6 – C2H2
e. C6H12O6 – (CH2O)6
55. The structural formula not only has the correct number of atoms but includes the bonding structure of the molecule (i.e., which atoms are bonded together). The correct structural formula is ….
a. CH3CH2CH2CH3
b. C4H10
c. C2H5
d. (C2H5)2
e. CnH2n+2
56. The atoms in molecules bond to one another through "sharing"of electrons. Ionic compounds on the other hand have particles that bond to one another through their mutual attraction between positive and negative charges. The statement which doesn’t relate to the ionic compound is ….
a. cations and anions attract one another
b. cations repel one another as do anions
c. positively charged atoms are called cations
d. negatively charged atoms are called anions
e. a number of cations must be less than a number of anions
57. The composition of ionic compounds is determined by the requirement that the compounds must be electrically neutral, because ….
a. number of cations = number of anions
b. charges of cations and anions must not balance
c. number of electrons = number of protons
d. charges of protons = charges of electrons
e. charges of cations > charges of anions

58. If Na+ combines with S2-, the formula of compound formed is ….
a. NaS
b. NaS2
c. Na2S
d. Na2S2
e. Na2S3
59. The ionic compounds formed from Ca2+ and PO43- is ….
a. CaPO4
b. Ca2PO4
c. Ca(PO4)2
d. Ca3(PO4)2
e. Ca2(PO4)3
60. The correct common name of the following compounds is ….
a. water (H2O2)
b. ammonia (NH)
c. glucose (C6H12O6)
d. sugar (CH4)
e. air aki (H2O)