Download Questions on unit 1

Questions on unit 1
Lesson 3
I. Complete the following statements:
1. The smallest part of the element that takes apart in a chemical
reaction is known as atom
3. The symbol of carbon atom is C while that of calcium atom is
Ca
4. The symbol of nitrogen atom is N while that of neon atom is
Ne
5- Na is the symbol of sodium atom, while that of sulphur atom is
S
7. The nucleus of the atom contains two different types of
particles, these are protons and neutrons
8. The atom consists of nucleus and electrons
9. In the nucleus, there are positively charged particles called
protons and neutral particles called neutrons
10. The mass of the atom is concentrated in the nucleus because
the mass of electron is negligible if it is compared to the mass of
Protons or neutrons.
11. Electrons have negative charge, while protons have positive
charge.
12. Electrons revolve around the nucleus in energy levels ,where
each one of them has its own energy
13. The number of neutrons in the nucleus of an atom may be
equal to or greater than the number of protons
14. The atom is electrically neutral because the number of
protons in the nucleus is equal to the number of electrons
15. The sum of the numbers of the protons . and neutrons in the
nucleus is known as mass number
II. Write the scientific term for each of the
following:
1. The fundamental building unit of matter that can take apart in
the chemical Reaction.
atom
2. The positively charged particle in the nucleus of an atom.
protons
3. The number of positively protons in the nucleus.
Atomic number
4. Neutral particle exists in the nucleus of an atom. Neutrons
5. Negatively charged particles of negligible mass that revolves
around the nucleus.
Electrons
6. A part of an atom exists in its center.
Nucleus
7. The number which is written at the bottom left side of the
element symbol.
Atomic number
8. The number which is written at the top left side of the
element symbol.
Mass number
9. The difference between the mass number and the atomic
number.
Number of neutrons
10. The sum of the numbers of protons and neutrons in the
nucleus.
Mass number
III. Put (√) in front of the right statement and (x) in
front of the wrong one and correct it :
1. The molecule is the smallest part of the element that can take
apart in the chemical reaction without changing.
(X)
The atom
2. (He) is the symbol of hydrogen element, while (H) is the symbol
of helium element. ( X )
( H )
( He )
3. The symbol of zinc is (Zn), while (Si) is the symbol of sulphur.
( X)
(S)
4. (Fe) is the symbol of iron.
5. The atom is electrically charged, while its nucleus is
electrically neutral. ( X)
Neutral – positively charged
IV. Give reason for:1. the atom is electrically neutral.
- Because the number of positive protons equal number
of electrons .
2. the mass of the atom is concentrated in the nucleus.
- Because the mass of electrons is negligible relative to
the mass of protons and neutrons
3. the electrons are distributed to fill the (K) level before
filling the (L)level.
- Because the k level has lower energy than L level
4. hydrogen molecule is diatomic, while helium molecule is
mono-atomic.
- Because hydrogen consists of 2 atoms while helium
consists of 1 atom
5. noble (inert)gases molecule are mono-atomic.
- Because inert gases consist of 1 atom
V. Write the name of the elements of the following
symbols:
1. H
8.K
2.He
9.Na
See p.24
5 .Cl
10. Cu
11.Br
VI. Write the electronic configuration of the
following:
,
Electronic config. In H K
He K
F K
L
Ne k
L
Na K
L
M
,
1
2
2
7
2
8
2
8
1
,
,
Then find:
1- Number of electrons in the outer level.
H=1, He=2, F=7, Ne=8, Na=1
2- The number of neutrons in each atom.
H=1-1=0,He4-2=2, F=18-9=9, Ne=20-10=10, Na=2311=12
3- the atomic number H =1,He=2, F=9, Ne=10, Na=11
4- the mass number H=1, He=4, F18, Ne=20, Na=23
5- Are those elements active or not.
H, F, Na are active the rest are inactive
VII. Write the symbols of the following
element:
1) Sodium
2) Potassium
3) Chlorine
Na
K
Cl
4) Nitrogen
N
5) Calcium
Ca
6) Aluminum
Al
7) Phosphorus
P