first term - first unit test - 2nd prep

1
The number of elements in Mendeleev's periodic table is.......... elements.
2
They are the elements, which have the properties of both metals and nonmetals.
3
The halogen, which can be prepared artificially is.........
4
All the following diseases are caused by biological pollution except.......... disease.
5
The element, whose atomic number is (17) is similar in its chemical construction to the element whose atomic number is ...........
6
All of the following metals react with water except........
7
The boiling point of liquefied nitrogen is..........
8
The pure water boils at.......... °C.
9
Elements of the same period in the modern periodic table have the same..........
10
In periods, by increasing the atomic number, the.........
11
........... form positive ions during the chemical reactions.
12
The electrolysis of acidified water gives hydrogen gas and oxygen gas at a ratio of........... by volume.
13
The atomic number of an element that exists in group (7A) and period (2) is.........
14
It is the ability of the atom in covalent molecule to attract the electrons of the chemical bond towards itself.
15
Arsenic increases the infection rate by.........
16
Mendeleev classified the elements of each group into......... sub-groups.
17
Each period in the periodic table starts with.........
18
............. is considered from halogens.
19
Which of the following behaviours causes radiant pollution ?..........
20
The number of elements which exist in nature is..........
21
The elements, which occupy the middle block (d) in the periodic table are called.......... elements.
22
By increasing the atomic number within group (1A), the .........
23
The halogen which exists in a liquid state is..........
24
All the following are natural water pollutants except..........
25
If the atomic number of an element is 15, so its group is located in...... block
26
They are the elements, which have less than four electrons in their outermost energy levels.
27
The metallic property of alkali metals increases by increasing their.........
28
A bottle is filled completely with water and put closed in the freezer. After sometime it breaks, because when water freezes............
29
The modern periodic table consists of......... vertical groups.
30
Hydrogen element belongs to..........
31
All the following are among the properties of water except............
32
The scientist, who discovered that the nucleus of atom contains positively charged protons is.........
33
It is an atom of nonmetallic element which gained an electron or more during the chemical reaction.
34
Alkali metals are considered from........... block groups.
35
In a water molecule, oxygen atom combines with two hydrogen atoms by two bonds.
36
The number of energy levels in the heaviest known atom is .......... levels.
37
The 3rd period starts with elements whose oxides are as the following........
38
All of the following are from the properties of alkali metals except they.......
39
Most alkali metals have........ density.
40
There are.......... bonds among the water molecules.
41
Noble gases are located in group............
42
......... is the least metallic element in group (1A).
43
The outermost energy level of any halogen contains......... electrons.
44
Water can dissolve.........
45
The snow crystal has.......... shape
46
The scientist who left vacancies in his table to be filled with suitable discovered elements in future is.........
47
They are the elements, which have more than four electrons in their outermost energy levels.
48
Halogens are considered from........block groups.
49
Increasing the concentration of ........... in drinking water causes blindness.
50
Liquid sodium is used in.........

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