In an atomic model that includes a nucleus, positive charge is
a. located in the space outside the nucleus.
b. spread evenly throughout an atom.
c. concentrated at multiple sites in an atom.
d. concentrated in the center of an atom.

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. the change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. the minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kj/mol.

What is the most important factor in determining climates.

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?