Final revision 2nd Sec 2T

When two atoms of element with an atomic number (8) combine Together Each atom shares by one electron Double pure covalent bond is formed (C) Polar covalent bond is formed (d) Nonpolar covalent bond is formed

• Ionic bond is formed
• Metallic bond is formed
• Hydrogen bond is formed
• Nonpolar covalent bond is formed

Noble gases molecules consist of ……………

• One atom

• Two atoms

• Three atoms

• four atoms

Which of the following molecules contains the highest number of a Lone pairs of electrons?

• H₂

• O₂

• Cl₂

• N₂

When two atoms of element with an atomic number (16) combine Together a- Each atom shares by one electron b-Double pure covalent bond is formed C- Polar covalent bond is formed d- Nonpolar covalent bond is formed

• b- Triple covalent bond is formed
• a- Each atom shares by two electrons
• d- Nonpolar covalent bond is formed
• c- Ionic bond is formed

Write the scientific term for each of the following statements: 1- A process in which bonds are broken in the reactant species and bonds are Formed in the product species. (…………………………. )

• Chemical formula
• Physical change
• Catalytic process
• Chemical reaction

Write the scientific term for each of the following statements: 2-A bond formed between two atoms one of them has low ionization energy and the other has a high electron affinity. ( ………………….. )

• Covalent bond
• Metallic bond
• Ionic bond
• Hydrogen bond

Write the scientific term for each of the following statements: 3- A covalent bond in which the electron density is symmetrically distributed. ( …………………… )

• Nonpolar covalent bond
• Polar covalent bond
• Ionic bond
• Metallic bond

Which molecule contains six bonding electrons?

• C2H₄

• H₂S

• NCl₃

• SF₆

Which molecule contains six bonding pairs ?

• C2H₄

• H₂S

• NCl₃

• SF₆

Give reasons for each of the following: Sodium chloride salt doesn't conduct electric current

• Sodium chloride salt doesn't conduct electric current in solid form due to the its ions don't moves

• Sodium chloride salt is a good conductor in solid form due to free electrons.
• Sodium chloride salt conducts electric current in liquid form only.
• Sodium chloride salt conducts electricity when heated.