A bond is __________ if the two atoms have the same electronegativity.

• polar covalent

• nonpolar covalent

• ionic

• polar ionic

Answer explanation

A bond is nonpolar covalent when the two atoms have the same electronegativity, meaning they share electrons equally. In contrast, polar covalent bonds occur when there is a difference in electronegativity.

A bond is __________ if the two atoms have different electronegativities.

• polar covalent

• nonpolar covalent

• ionic

• polar ionic

Answer explanation

A bond is polar covalent when two atoms with different electronegativities share electrons unequally, resulting in a dipole moment. This distinguishes it from nonpolar covalent bonds, where electronegativities are similar.

Tags

NGSS.HS-PS1-1

The compound ammonia (NH₃) is ______________.

• polar covalent

• nonpolar covalent

• ionic

• polar ionic

Answer explanation

The compound ammonia (NH₃) is polar covalent because it has a significant difference in electronegativity between nitrogen and hydrogen, resulting in a dipole moment. This makes NH₃ a polar molecule.

The compound carbon dioxide (CO₂) is ______________.

• polar covalent

• nonpolar covalent

• ionic

• polar ionic

Answer explanation

Carbon dioxide (CO₂) has a linear molecular geometry, and the dipoles from the polar covalent bonds between carbon and oxygen cancel each other out, making it a nonpolar covalent compound.

Oxygen gas (O₂) is ______________.

• nonpolar covalent

• polar covalent

• polar ionic

• ionic

Answer explanation

Oxygen gas (O₂) consists of two oxygen atoms sharing electrons equally, resulting in no charge separation. This equal sharing classifies O₂ as a nonpolar covalent molecule, making 'nonpolar covalent' the correct choice.

Tags

NGSS.HS-PS1-2

The atoms in a nonpolar bond ______________.

• share electrons evenly (symmetrically)

• are a result of electrostatic attraction between positive and negative ions

• share electrons unevenly (asymmetrically)

• are a result of electrostatic repulsion between positive and negative ions

Answer explanation

In a nonpolar bond, atoms share electrons evenly (symmetrically) because they have similar electronegativities, resulting in a balanced distribution of charge.

Tags

NGSS.HS-PS1-2

The atoms in a polar bond _______________.

• share electrons evenly (symmetrically)

• are a result of electrostatic attraction between positive and negative ions

• share electrons unevenly (asymmetrically)

• are a result of electrostatic repulsion between positive and negative ions

Answer explanation

In a polar bond, the atoms share electrons unevenly (asymmetrically) due to differences in electronegativity, leading to partial positive and negative charges.

Tags

NGSS.HS-PS1-2

The compound hydrogen monofluoride (HF) is _______________.

• ionic

• polar ionic

• polar

• nonpolar

Answer explanation

Hydrogen monofluoride (HF) is a polar molecule due to the significant electronegativity difference between hydrogen and fluorine, resulting in a dipole moment. Thus, the correct classification is polar.

Tags

NGSS.HS-PS1-3

Carbon and fluorine form a ______________ because of their difference in electronegativity.

• polar covalent

• nonpolar covalent

• polar ionic

• ionic

Answer explanation

Carbon and fluorine have a significant difference in electronegativity, leading to an unequal sharing of electrons. This results in a polar covalent bond, where one atom is more electronegative than the other, creating a dipole.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The more electronegative atom will ______________.

• attract less electrons

• repel more electrons

• attract more electrons

• share electrons evenly

Answer explanation

The more electronegative atom has a stronger attraction for electrons, meaning it will attract more electrons towards itself. This is why the correct answer is 'attract more electrons'.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2