Which one of the five categories of sensory receptors is primarily dedicated to external stimuli?
BSC2010 Lecture 2 Chapter 2 – 24 August 2016 • In atoms, like charges repel each other and opposite charges attract each other • Number of electrons equals the number of protons • Dalton’s number = mass of one proton or neutron • Element: one pure substance that contains only one kind of atom • Natural elements: carbon, oxygen, nitrogen, hydrogen, oxygen, phosphorus • Number of protons doesn’t change and the number of neutrons can change (isotopes) • Behavior of electrons determines whether a chemical bond will form and what shape the bond will have • Atoms with unfilled shells undergo chemical reaction • When a shell is unfilled, it is unstable • There are several kinds of chemical bonds: • Ionic bond: ions are charged particle that form when an atom gains or loses one or more
