Download First Term Science Al-Karma Language School Prep 2 Question (1

First Term
Al-Karma Language School
Science
Prep 2
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Question (1):
Complete the following statements:
1)-The scientist who discovered the presence of protons in the nucleus is
Rutherford.
2)-All alkali metals are good conductors of Heat and electricity.
3)-In groups (17), the electro negativity of chlorine (17Cl) is more than
that of bromine
(35Br).
4)-Elements of group (1A) are known as alkali metals, while elements of
group (17) are called halogens.
5)-The modern periodic table consists of 7 periods and 18 groups.
6)-Metals react with oxygen giving metal oxides which is known as basic
oxides.
7)-Cobalt 60 is used in food preservation as it emits gamma rays which
prevent reproduction of microbial cells.
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First Term
Al-Karma Language School
Science
Prep 2
8)-In 1913, the New Zealand scientist Rutherford discovered that the
nucleus of the atom contains positive protons.
9)-Mendeleev arranged the elements ascending according to atomic
weight, while Moseley arranged them ascending according to atomic
number.
10)-Calcium (Ca) and Magnesium (Mg) elements are examples of
alkaline earth metals.
11)-The valency energy level of halogen contains seven electrons, while
that of alkaline earth metal has two electrons.
12)-Sodium and potassium are kept under the surface of kerosene to
prevent them from the reaction with oxygen (moist air).
13)-Each period in the modern periodic table starts with metals and ends
with inert gases.
14)-The positive ion carries a number of positive charges equals to the
number lost electrons.
15)-An element whose electronic configuration is (2,8) so, it exists in
group 8A or zero and period 2 in the modern periodic table.
16)-The new number of group (5A) is 15, while that of zero group is 18.
17)-Metalloids have properties of metals and non metals and silicon (Si)
is one example of them.
18)-Pure water boils at 100̊C and freezes at 0̊C.
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First Term
Al-Karma Language School
Science
Prep 2
19)-The high latent heat of water makes it able to resist the change
from a state to another, while the high specific heat of water makes it
able to absorb or lose large amount of heat without changing its
temperature.
Question (2):
Write the scientific term:
1)-The group of elements that have higher densities than alkali metals
densities.
2)-The part from million million part of a meter.
(Alkaline Earth metals)
(Picometer)
3)-An element that gains electrons during chemical reactions.
(Non-metals)
4)-Oxides produced from the reaction of metals with oxygen.
(Basic oxides)
5)-The arrangement of metals in descending order according to their
chemical activities.
(Chemical activity series)
6)-The ability of the atom in covalent molecule to attract the electrons
of the chemical bond to itself.
(Electro negativity)
7)-The number of protons inside the nucleus.
(Atomic number)
8)-The non metal element which is used in preservation of the cornea of
the eye.
(Liquid nitrogen)
9)-Metalloid which is used in the manufacture of electronics.
(Silicon)
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First Term
Al-Karma Language School
Science
Prep 2
10)-Metals of d- block elements which start at period four of the
modern periodic table.
11)- Elements of group 18.
(Transition metals)
(Nobel gases)
12)-The group which is located on the right side of the periodic table
before zero group.
(Halogens)
13)-The table in which elements are classified in an ascending order
according to their atomic number and the way of filling energy levels with
electrons.
(Modern periodic table)
14)-Non metallic atom that gains electron or more during chemical
reactions.
(Negative ion)
15)-The gas evolved on adding dilute hydrochloric acid to magnesium
strip.
Mg +2HCl
MgCl2 + H2
16)-The halogen which exists in liquid state.
(Hydrogen gas)
(Bromine)
17)-A molecule consists of two hydrogen atoms and one oxygen atom.
(Water molecule H2O)
18)-Compounds, most of them dissolve in water.
(Ionic compounds)
19)-The bond which binds oxygen atom with hydrogen atom in water
molecule.
(Single covalent bond)
20)-The kind of bond which binds water molecules together.
(Hydrogen bond)
21)-The shape of ice crystals.
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(Hexagonal shape)
First Term
Al-Karma Language School
Science
Prep 2
22)-The positive ions which are produced from water ionization.
(Hydrogen ion)
Question (3):
Give reasons for:
1)-Liquified nitrogen is used in preservation of cornea of the eye.
Due to the decrease of its boiling point (-196̊ ).
2)-Sodium ion (Na +) and fluoride ion (F-) have the same electronic
configuration.
Because during the chemical reactions, sodium
11Na
atom
loses one electron and fluorine 9F atom gains one electron so
the number of electrons become 10 electrons so the same
electronic configuration.
3)-Elements of group (1A) are known as alkali metals.
Because they react with water forming alkaline solutions.
4)-Water is more Polar than ammonia.
Because the difference in the electro negativity between
oxygen and hydrogen is greater than the difference between
nitrogen and hydrogen.
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First Term
Al-Karma Language School
Science
Prep 2
5)-Mendeleev had to put more than one element in one cell.
Due to the similarity in their atomic weight, chemical and
physical properties.
6)-The atomic size of elements in the same period decreases as their
atomic numbers increases.
Because the attraction force between the positive nucleus and
the outermost negative electrons increases in the period.
7)-Sodium fires don't put off with water.
Because sodium reacts with water and hydrogen gas
evolved with pop sound.
2Na+ 2H2O
2NaOH + H2
8)-Cobalt 60 is used in preservation of food.
Because it emits gamma rays which prevent the reproduction of
microbes and kill them.
9)-Silicon slides are used in the manufacture of electronics.
Because it is metalloid and its ability to conduct electricity
depends on the temperature.
10)-Mendeleev left gaps in his periodic table.
Because he predicted the discovery of new elements.
11)-Group (17) elements are known as halogens.
Because they react with metals forming salts.
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2K +Br2
2KBr
First Term
Al-Karma Language School
Science
Prep 2
12)-Alkali metals are monovalent elements.
Because their atoms have only one electron in their outermost
energy level.
13)-Cesium (Cs) is the most metallic element.
Because the metallic property increases by increasing the
atomic number in the groups.
Question (4):
Choose the correct answer:
1)-Transition elements appear starting from period --------.
(2-3-4-5)
2)-Burning carbon in air produces -----------.
(CO- C02 –CuO- HCl)
C +O2
CO2
3)-The molecule of halogen is composed of -------- atoms.
(2- 1 - 3 – 4)
4)-The number of elements in Mendeleev's table is ---------.
(92- 116 – 76 – 67)
5)-During chemical reaction of halogens, they -------- electrons.
(gain one – lose one – gain two – share one)
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First Term
Al-Karma Language School
Science
Prep 2
6)-The atomic number of the elements which lies in period (4) and
group (2A) is ----------.
(4 – 18 – 12 – 20)
2 8 8 2
7)-The liquified nitrogen is used in preservation of cornea of the eye
because ------------.
(it has high boiling point – it has high freezing point – it has low
freezing point – it has low boiling point)
Question (5):
A)-Mention one use or importance for each of the following:
1)-Liquid sodium.
It is used in transferring heat from inside the nuclear
reactor to outside to generate electricity.
2)-Liquid nitrogen.
It is used in preservation of cornea of eye.
B)-Locate the following elements in the modern periodic table:
1)-11Na
2 8 1
8
P= 3
G = 1A
First Term
Al-Karma Language School
Science
Prep 2
2)-3Li
2 1
P = 2
G =1A
P= 3
G = 7A
3)-17Cl
2 8 7
4)-1H
1
P = 1
,
G = 1A
C)-Correct the underlined words:
1)-The electro negativity of elements increase in the groups by
increasing their atomic number.
Metallic property or atomic size.
2)-The density of potassium is larger than the density of calcium.
smaller than
3)-Water has low latent heat and specific heat.
high
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First Term
Al-Karma Language School
Science
Prep 2
4)-The density of water (liquid) less than the density of ice (solid).
more than
D)-The opposite figure shows a set of the periodic table:
1)-What is the name of the shaded group?
Halogens.
2)-What is its block?
P-block.
3)-State the physical sate of their elements?
Fluorine and chlorine are gases – Bromine is liquid – Iodine is solid.
4)-What is the new number of this group in the modern periodic table?
The new number is (17).
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First Term
Al-Karma Language School
Science
Prep 2
Question (6)
A)-What is the atomic number of each of the following elements:
1)- Element (X) which lies at period (2) and group (3A).
X
2 3
atomic number = 5
.
2)- Element (Y) which lies at period (3) and group (5).
Y
2 8 5
atomic number = 15
B)-Write the chemical equation that illustrate:
1)-Reaction of carbon dioxide with water.
CO2 + H2O
H2CO3 (Carbonic acid)
2)-Reaction of magnesium with dilute hydrochloric acid.
Mg + 2HCl
MgCl2 + H2
3)-Reaction copper with hydrochloric acid .
Cu + HCl
No reaction
4)-Reaction chlorine with potassium bromide.
Cl2 + 2KBr
11
2KCl + Br2.
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First Term
Al-Karma Language School
Science
Prep 2
5)-Reaction bromine with potassium iodide.
Br2 + 2 KI
2KBr + I2 .
6)-Reaction potassium with bromine.
2K + Br2
2KBr.
C)-Show by chemical equations the effect of water on:
1)-Sodium.
2Na + 2H2O
2NaOH + H2 (Hydrogen gas).
2)-Carbon dioxide.
CO2
+ H2 O
H2CO3 (Carbonic acid)
3)-Magnesium oxide.
MgO + H2O
Mg(OH)2 (Magnesium hydroxide).
4)-Copper.
Cu + H2O
12
No reaction