Chemistry(II) Chapter 1 & 2

              1.           Which of the following pairs are chemically
                            dissimilar?

                           (A) Na and K                             (B) Ba and Sr
                           (C) Zr and Hf                 (D) Ca and Zn.

               2.         The total number of inner transition elements
                           is

                           (A) 10                 (B) 14
                           (C) 28                 (C) 30

               3.         The alkali metal which is liquid at 15oC is

                           (A) K                  (B) Cs
                           (C) Na                (D) None

               4.         Which of the following ion will form most water
                           soluble hydroxide?

                           (A) K+                (B) Ni2+
                           (B) Zn2+             (C) Al3+

               5.         Which of the following has greatest tendency to lose electron?

                           (A) F                  (B) Fr
                           (B) S                  (C) Be.

               6.         The oxide of which of the following elements will be acidic in character

                           (A) Mg                (B) Rb
                           (C)  Li                 (C) CI

               7.         Which of the following is isoelectronic with carbon atom?

                           (A) Na+             (B) Al3+
                           (C) O2-              (D) N+

               8.         Which of the following ions are paramagnetic in character?

                           (A) Zn2+              (B) Cu+
                           (C) Ni2+              (D) Ag+

               9.         Ca2+ ion is isoelectronic with

                           (A) Mg2+            (B) Na+
                           (C) Ar                (D) Kr

               10.        Gradual addition of electronic shells in the noble gases causes a decrease in their

                           (A) Ionization energy        (B) atomic radius
                        (C) Boiling point                (D) density


               11.        Which of the following has highest first ionization potential?

                           (A) Carbon                      (B) Oxygen
                           (C) Nitrogen                    (C) Boron.

               12.        Which of the following has the smallest size?

                           (A) Na+                          (B) Mg2+
                           (C) Al3+                          (D) CI

               13.        Which of the following element has the maximum  electron affinity?

                           (A) F                                  (B) S
                           (C) I                                   (D) CI.

               14.        Which of the following is isoelectronic as well  as has the same structure as that of N2O ?

                           (A) N3H                               (B) H2O
                           (B) NO2                               (C) CO2

               15.        The atomic radius increases as we move down a group because

                           (A) Effective nuclear charge increases
                            (B) Atomic mass increases
                           (C) Additive electrons are accommodated in  new electron  level
                           (D) Atomic number increase.

               16.        Which one of the following is an incorrect statement?

                             (A)  The ionization potential of nitrogen is greater than that of chlorine
                             (B)  The electron affinity of fluorine is greater  than that of chlorine
                             (C)  The ionization potential of beryllium is greater than that of boron
                             (D) The electronegativity of fluorine is greater than that of chlorine.

               17.        Electron affinity depends on

                           (A) Atomic size          
                           (B) Nuclear charge
                           (C) Atomic number
                           (D) Atomic size and nuclear charge both.

               18.        Two elements whose eletronegativities are 1.2    and 3.0, the bond formed between them                      would be

                           (A) Ionic
                           (B) covalent
                           (C) Coordinate  
                           (D) metallic.

               19.        Ionic radii are

                           (A) Directly proportional to square of effective nuclear charges
                           (B) Inversely proportional to effective nuclear charge
                           (C) Inversely proportional to square of effective nuclear charge
                           (D) Directly proportional to effective nuclear charge.

               20.        Which of the following oxides is atmospheric in character?

                            (A) CaO                    (B) CO2
                           (C) SiO2                    (D) SnO2

               21.        Mark the correct statement:

                           (A) Na+ is smaller than Na atom
                           (B) Na+ is larger than Na atom
                           (C) CI- is smaller than CI atom
                           (D) CI- and CI are equal in size

               22.        Who introduced the zero groups?

                            (A) Lothar Meyer               (B) Lockery
                           (C) Mendleev                     (D) Ramsay

                23.        Element, of group I-B are called

                           (A) Representative elements
                           (B) Transition elements
                           (C) Rare earth
                           (D) Coinage metals

               24.        The element with Z = 24 is placed in the period

                           (A) 5                                    (B) 2
                           (C) 3                                    (D) 4

               25.        Which is the part of metalloids?

                           (A) NA and K                        (B) F and CI
                           (C) None of these                 (D) Cu and Au

                26.        Which one of the following has the maximum electron affinity?
                           (A) I                             (B) Br
                           (C) CI                           (D) F

               27.        On electrolysis of NaH, hydrogen is liberated

                           (A) At anode               (B) in the electrolyte
                           (C) At cathode            (D) none of them

                28.        Elements with greater number of electrons have _________values of ionization energy.

                             a) Only one                   b) More than one
                             c) Zero                          d) Infinite

                 29.        Which of the following possess maximum hydration power?

                              a) Na+               b) K+
                             c) Mg+2             d) Ca+2

                  30.        Higher value of electron affinity  means_________
                               a. Atom will lose electron easily
                               b. Atom will gain electron easily
                               c. Atom may form di-positive ion
                               d. The reason is unknown

31.        Melting points of VII-A group ___________         down the group

a.    Increase                 b     Decrease
c.    Remain constant     d.    No regular trend

32.        Oxidation state of an atom represents______
a. No. of electrons gained
b. No. of electrons lost
c. No. of electrons gained or lost
d.   None of above correctly represent it

33.        Mendeleev’s periodic table was based on

a) Atomic number    b) Atomic mass
c) Atomic volume     d) Electronic configuration

34.        Elements present in a same group have the same

a) Atomic number      
b) Molecular weight
c) Chemical properties
d) Electronic configuration

35.        “s” and “p” block elements are also called

a)     Transition elements
b)    Inert elements
c)     Typical elements
d)    Rare earth elements

36.        What is the symbol of the element with only three electrons and three protons?

a) Li                              b) C
c) Ag                            d) Cu

37.        Elements with seven electrons in their valence shell are known as

a) Inert                          b) Lanthanides
c) Halogens                  d) Alkali metals

38.        Which of the following pairs of elements are chemically most similar?

a) Na and Al                  b) Cu and Cu
c) S and F                     d) Sc and Zn

39.        A student of chemistry will identify positively the following symbols as sodium
            a)                           b)
            c)                            d)

40.        In the periodic table each period begins with a metal, which is

a)     Most electronegative
b)    Most electropositive
c)     Less electropositive
d)    Less electronegative

41.        Which one of the following is not a coinage metal?

a) Au                            b) Cu
c) Ag                            d) Pd

42.        Which is the most metallic element of 2nd period?

a) Lithium                      b) Beryllium
c) Boron                       d) Carbon

43.        The outer most orbital involved in chemical bonding is called

a) Molecular orbital        b) Complete orbital
c) Valence orbital          d) Free orbital

44.        Elements, which form basic oxides are

a) Electropositive          b) Electronegative
c) Inert                          d) None of these

45.        Which of the following has the most basic character?

a) Na2O                         b) MgO
c) Al2O3                                                  d) P2O3

46.        Which of the following is smallest in size?

a) K+1                                                        b) O-2
c) F-1                                                         d) Na+

47.        Ionization energy is lowest for

a) Inert gases               b) Halogens
c) Alkali metals             d) Alkaline earth metals
48.        An isotope of hydrogen is

a) Neptunium                 b) Plutonium
c) Thorium                     d) Tritium

49.        With respect to chlorine, hydrogen will be

a) Electropositive          b) Electronegative
c) Neutral                      d) None of these

50.        Which of the following has the highest electron affinity?

a) 1S2 2S2 2P3                               b) 1S2 2S2 2P6 3S1
c) 1S2 2S2 2P5                               d) 1S2 2S2 2P5

Sex Linked, Sex Limited and Sex Influenced Traits

For most inherited traits, the gender of the bearer of the genes is immaterial. Characteristics like free earlobes, fur color, etc., generally operate the same in males as they do in females.

But there are exceptions. These fall into three primary categories.

Sex Linked Traits are traits whose loci are literally on the sex chromosomes, so their transmission from generation to generation is affected by the sex chromosome complement of the individual. In any species with non-homologous sex chromosomes, these traits can be significant.

The first demonstration of sex linkage was the white eye gene in Drosophila, the fruit fly which has become so important to the study of classical genetics. Normal fruit fly eye color is a dull brick red. Mutations in this gene cause the eyes to be white. The white allele is recessive, but it was quickly determined that the inheritance pattern for this gene was different from those of other genes being studied. In some kinds of matings, reciprocal crosses produced different results, something which had never been observed to happen with other genes. Not only that, but in some kinds of matings, the results for the male offspring would be different from the results for the female offspring. For instance, if a white-eyed female was mated to a red-eyed male, all of the female offspring would be red eyed, but all of the male offspring would be white eyed.

It turned out that this particular eye color gene was literally located on the X chromosome. Since females have two X chromosomes and males have only one, genetic effects in the two genders are different. And since females contribute an X to each offspring, male or female, and males contribute X chromosomes only to female offspring, naturally transmission patterns were different in different kinds of matings.

“Linkage” refers to the physical connection that exists between genes whose loci are on the same chromosome. Genes on the X chromosome are all linked to each other—thus they are X-linked.

X-linked traits have a number of interesting aspects. First, because females possess two X chromosomes and males possess only one, X-linked recessive traits appear far more commonly in males than in females. This is clear from simple statistics. A male will show the X-linked recessive trait due to receiving only a single copy of the allele, because he has no second X chromosome to carry a dominant allele which might hide the recessive. Females must inherit the recessive trait twice to show it, just as they do for any other recessive trait. This is a much more unlikely outcome. This is the source of the misconception that only males can display X-linked traits like color blindness.

Another interesting observation about X-linked traits is that males always receive their X chromosomes from their mothers, so they also receive any X-linked traits from their mothers. Their fathers have no contribution for those genes (though, of course, they do for the genes on all of the other chromosomes). Daughters inherit one X from each parent. And of course, the one X they inherit from their fathers will be the only X he has.

There are also a very few genes which are Y-linked (or holandric). Y-linked genes are carried on the Y chromosome, and are thus passed directly from father to son. Every son has a copy of his father’s Y chromosome. In any pedigree showing unbroken lines of male descent, all of the connected males have copies of the same Y chromosome, and thus share any Y-linked characteristics.

One final note about that very significant white-eyed Drosophila gene. In combination with a strange chromosomal anomaly called attached-X, this gene also produced the first direct evidence that genes were literally carried on chromosomes. Useful little gene.

Gender matters for a couple of other kinds of traits as well.

Sex limited traits are generally autosomal, meaning that they are not found on the X or Y chromosomes. The genes for these traits behave exactly the same way that any autosomal gene behaves. The difference here comes in the expression of the genes in the phenotype of the individual. Sex-limited traits are expressed in only one gender. The traits are generally associated with primary or secondary sexual characteristics, and thus are expressed only in the gender which utilizes those characteristics. For example, there are genes which influence how much milk a lactating mother produces when she’s nursing a baby. These genes are carried by both males and females, but only females ever express them. Another example is the condition cryptorchidism (undescended testicles). In development, the primary sexual organs of males (testicles) and females (ovaries) develop from the same embryonic tissue. This tissue is located low in the abdomen, in roughly the same position ovaries are located in fully developed females. But in fully developed males, the testicles are not located in the abdomen. Late in development, they move from their abdominal position, through the inguinal canal into the scrotum, which is essentially a small skin bag which hangs outside the body. This voyage is important, because the temperature inside the abdomen is too high for the development of viable sperm. Cryptorchidism is a genetically determined condition in which one or both testicles fail to make this voyage, and remain in the abdomen. (This is generally surgically corrected very early, because not only is a cryptorchid male sterile, but the undescended testicles are at increased risk for testicular cancer). The genes for this condition are autosomal; males and females each carry two alleles. But only males can possible exhibit the condition, because only males show the normal condition for testicle behavior and position.

Sex influenced traits are also autosomal, meaning that their genes are not carried on the sex chromosomes. Again, what makes these traits unusual is the way they are expressed phenotypically. In this case, the difference is in the ways the two genders express the genes.

One classic example of a sex influenced trait is pattern baldness in humans (sometimes called “male pattern baldness,” though the condition isn’t restricted to males). This gene has two alleles, “bald” and “non-bald.” The behaviors of the products of these genes are highly influenced by the hormones in the individual, particularly by the hormone testosterone. In the presence of high levels of testosterone, the baldness allele has a very powerful influence. In the presence of low levels of testosterone, this allele is quite ineffectual. All humans have testosterone, but males have much higher levels of this hormone than females do. The result is that in males, the baldness allele behaves like a dominant allele, while in females it behaves like a recessive allele. As in all cases, dominance only matters in the heterozygote, so this means that heterozygous males will experience hair loss and heterozygous females will not. Even homozygous females may experience no more than a thinning of their hair, but many develop bald spots or have receding hairlines.

An interesting note about this gene is that it is often incorrectly identified as X-linked because of an illusion that males inherit it from their mothers. Males can inherit baldness from either parent, but if a son gets it from his father, both father and son will be bald, and nobody really notices, as we expect sons to look reasonably like their fathers. But if a son loses his hair and his father doesn’t, that’s noteworthy, and the conclusion people have drawn (correctly) is that Junior inherited baldness from his mother. But recall that with X-linkage sons always inherit traits from their mothers and never from their fathers. In the case of baldness, a son can inherit from either parent. It’s just that we notice it more in the case of inheritance from the mother. This is a kind of casual “sampling error,” in which we subconsciously only “count” the surprising cases and conveniently forget the more ordinary ones.

Another instance of a sex influenced trait is in singing voice. The genetic influences that determine whether a person will have a high singing voice or a low one are autosomal, but the effects of the alleles are opposite in the two genders. The same allelic combination which produces a high soprano in a woman causes a male to be a low bass. And the combination that producers a high tenor in males produces a low contralto in females.