Chemistry Unit

The Lewis structure of N₂H₂ shows __________.

• a nitrogen-nitrogen triple bond

• a nitrogen-nitrogen single bond

• each nitrogen has one lone pair

• each nitrogen has two lone pairs

• each hydrogen has one lone pair

In the nitrite ion (NO₂^-), __________.

• both bonds are single bonds

• both bonds are double bonds

• both bonds are the same because of resonance

• there are 20 valence electrons

• there is one single and one double bond

The ability of an atom in a molecule to attract electrons is best quantified by the ______.

• electronegativity

• paramagnetism

• diamagnetism

• electron change-to-mass ratio

• first ionization energy

A valid Lewis structure of _______ cannot be drawn without violating the octet rule.

• NF₃

• IF₃

• PF₃

• SbF₃

• SO₄^2-

Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate an octet?

• N

• C

• H

• O

• B

In the resonance form of ozone shown, the formal charge on the central oxygen atom is _______.

• 0

• +1

• -1

• +2

• -2

Bond enthalpy is __________.

• always negative

• always positive

• sometimes positive and sometimes negative

• always zero

• unpredictable

Tags

NGSS.HS-PS1-4

As the number of covalent bonds between two atoms increases, the distance between the atoms ______ and the strength of the bond between them ______.

• increases, increases

• decreases, decreases

• increases, decreases

• decreases, increases

• is unpredictable

The Lewis structure of the CO₃^2- ion is

• 
• 
• 
• 
• 

Tags

NGSS.HS-PS1-2

Which of these bonds takes the most energy to break?

• single

• double

• triple

• quadruple

Tags

NGSS.HS-PS1-4