Lesson 3

Q.10: Mention an activity to Explain:

1-Matter is composed of molecules.

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2- Molecules of matter in a continuous motion.

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3- The presence of the intermolecular spaces between molecules.

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4- The presence of different attraction force between molecules.

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1- Positive charged particles exist inside the nucleus.

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2- Negative charged particles revolve around the nucleus.

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3- Number of positive charges that found inside the nucleus.

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4- The amount of energy gained or lost for the electron to transfer from an energy level to another. [----------------------------]

Q. 2: Give reason for each of the following:

1- Scientists use the symbols for the elements.

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2- The nucleus of the atom has a positive charge.

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3- The nucleus of the atom is concentrated in its nucleus.

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4- Mostly, the mass number is larger than the atomic number.

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5- The atom is electrically neutral in the normal state.

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6- The equation (2N²) is not applied for the levels higher than the 4^th one.

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7- The energy level (M) is filled with (18) electrons.

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8- The energy level (K) is filled with electrons before the energy level (L).

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9- The atom (₁₀Ne) can't share in the chemical reactions in the normal conditions.

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10- The atom (₁₁Na) is chemically active.

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Q. 3: The following figures represent the electronic configuration for some elements:

Study these figures well then answer:

a- The atomic no. for each atom. ------------------------------------------------------

b- The mass no. for each atom. --------------------------------------------------------

c- The no. of electrons for the outer most energy level. ----------------------------

d- The no. of energy levels that filled with electrons. ------------------------------

e- No. of neutrons for each atom. -----------------------------------------------------

Q. 4: Choose the correct answer

1- The symbol of copper atom is -------------. [C - Cu - Ca]

2- The symbol of Sodium atom is -------------. [S - Si - Na]

3- The energy level that filled with (18) electrons is -------------. [K - L - M]

4- The energy level that has the most energy is -------------.

[(K) Level – (Q) level – (N) level]

5- The smallest individual unit of matter which can share in chemical reaction is -------------. [Molecule - atom - compound]

6- An element has atomic no. = 17 and mass no. = 35, the no. of its neutrons is = -------------. [11 - 35 - 18]

Q. 5: can you define me:

1- Atom: ----------------------------------------------------------------------------------.

2- Mass no.: ------------------------------------------------------------------------------.

3- Atomic no.:----------------------------------------------------------------------------.

4- Quantum: -----------------------------------------------------------------------------.

Q.6: Complete the following:

1- The nearest energy level to the nucleus is --------- and the farthest is --------.

2- The proton has ----------- charged, while the electron has ----------- charged.

3- The no. of electrons that saturates energy level can be calculated by the relation------------------------.

4- The outer energy level of the nucleus can't carry more than --------------- or --------------- by electron to travel from level to anther.

5- Quantum is the amount of energy that ---------------- or --------------- by the electron to travel to another.

6- The symbol of the Calcium is ------------- and Copper is -------------.

7- Mass no. = ---------------- + -----------------.

8- Atomic no. is the number of ---------------- that exist inside the nucleus of the atom or the no. of -------------- that revolve around the nucleus.

9- Number of the neutrons = ------------------ ـــ-------------------

Q.7: In the potassium (_K) study the following:-

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b- No. of neutrons: ---------------------------------------------------------------------

c- No. of protons: ----------------------------------------------------------------------

d- No. of electrons: --------------------------------------------------------------------

e- Atomic no.: --------------------------------------------------------------------------

f- Mass no.: -----------------------------------------------------------------------------

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Q. 8: Complete the table: