2ND CA TEST CHEMISTRY YEAR 10

During a chemistry class, James is trying to remember the electron configuration of oxygen. He recalls that it has a specific arrangement of electrons in its orbitals. What is the electron configuration of oxygen?

• 1s² 2s² 2p²

• 1s² 2s² 2p⁵

• 1s² 2s² 2p⁴

• 1s² 2s² 2p³

In a chemistry class, Samuel is trying to determine how many valence electrons sodium has while studying the periodic table. Can you help him?

• 3

• 1

• 5

• 2

Explain the process of ionic bonding between sodium and chlorine.

• Chlorine loses an electron to sodium, resulting in Cl+ and Na- ions.

• Ionic bonding occurs when sodium and chlorine combine without any electron transfer.

• Ionic bonding occurs when sodium transfers an electron to chlorine, forming Na+ and Cl- ions that attract each other.

• Sodium and chlorine share electrons equally to form a covalent bond.

Describe how covalent bonds are formed between two nonmetals.

• Covalent bonds are formed by the transfer of electrons from one nonmetal to another.

• Covalent bonds are created when nonmetals lose their outer electrons completely.

• Covalent bonds occur only between metals and nonmetals.

• Covalent bonds are formed by the sharing of electron pairs between two nonmetals.

What is the electron configuration of a magnesium ion (Mg2+)?

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁵

• 1s² 2s² 2p⁶

• 1s² 2s² 2p⁶ 3p⁶

How does the electronegativity difference affect ionic bonding?

• A small electronegativity difference leads to stronger covalent bonds.

• A significant electronegativity difference leads to the formation of ions and strong ionic bonds.

• Electronegativity difference has no effect on ionic bonding.

• Ionic bonds are formed only when electronegativity is equal.

Describe the characteristics of covalent compounds.

• Covalent compounds can only exist as solids at room temperature.

• Covalent compounds have low melting and boiling points, poor electrical conductivity, and can exist in various states at room temperature.

• Covalent compounds are good conductors of electricity.

• Covalent compounds have high melting and boiling points.

Explain the role of electron sharing in covalent bonding.

• Electron sharing leads to the formation of ionic bonds.

• Covalent bonds are formed by the transfer of electrons between atoms.

• Electron sharing in covalent bonding allows atoms to achieve stability by filling their outer electron shells, leading to the formation of strong chemical bonds.

• Electron sharing results in the repulsion of atoms, weakening the bond.

What type of bond is formed when electrons are shared between two atoms?

• Hydrogen bond

• Covalent bond

• Metallic bond

• Ionic bond

Which of the following elements has the highest electronegativity?

• Chlorine

• Fluorine

• Oxygen

• Nitrogen