1. What do molecules and polyatomic ions have in common?
QUESTION:
What do molecules and polyatomic ions have in common?
A. They consist of at least two atoms sharing electrons
B. They consist of at least two atoms held together by ionic bonds
C. The number of protons is equal to the number of electrons
SCRIPT:
What do molecules and polyatomic ions have in common?
A. They consist of at least two atoms sharing electrons
B. They consist of at least two atoms held together by ionic bonds
C. The number of protons is equal to the number of electrons
PAUSE
The correct answer is A. Molecules and polyatomic ions consist of at least two atoms sharing electrons.
Choice B is wrong. Atoms sharing electrons are said to be held together by covalent bonds, not ionic bonds.
CROSS OUT ionic
CALLOUT “should be covalent”
CHOICE C applies only to molecules.
CLICK
Molecules are neutral. The total number of protons in a molecule is equal to the total number of electrons.
However, polyatomic ions have an overall nonzero charge. For a molecule, the charge is zero.
PAUSE CLICK END RECORDING
True for molecules, not true for polyatomic ions.
Charge = (#protons) – (#electrons) = 0 for molecules; not 0 for ions

2. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08