A student drops a white tablet into a glass of water, producing carbon dioxide gas. This is a demonstration of
A. a change of state.
B. a chemical reaction.
C. the creation of matter.
O D. the movement of electricity.

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.

As we move from left to right across the periodic table, what is the general trend? a) atomic radii increase. b) electronegavitiy decreases. c) nuclear shielding increases. d) metallic character decreases.

An unknown substance has been shown to have metallic bonds. which of the following is most likely a property of this substance? a. low conductivity b. low boiling point c. high malleability d. high solubility in water