BIOS 251 EXAM 1 QUESTION BANK 2026 BODY SYSTEMS REVIEW UPDATED A+

BIOS 251 EXAM 1 QUESTION BANK 2026
BODY SYSTEMS REVIEW UPDATED A+

◉ Neutron.
Answer: 0 charge.


◉ Electrons.
Answer: Much smaller mass than protons or neutrons, -1 charge.


◉ Atomic number.
Answer: Number of protons in an atom.


◉ Mass number.
Answer: Total number of protons + neutrons in an atom.


◉ Atomic weight.
Answer: Average mass of an atom of that element.


◉ Isotopes.
Answer: Changing the number of neutrons will change the mass
number and atomic weight.

, ◉ Ions.
Answer: Changing the number of electrons will change the electrical
charge of the atom.


◉ Molecules.
Answer: Atoms can react with either atoms of the same element or
atoms of different elements to create molecules.


◉ Valence electrons.
Answer: The electrons in the outermost shell of an atom that are the
most important for chemical reactions.


◉ Cation.
Answer: Protons > Electrons = Cation (+).


◉ Anion.
Answer: Electrons > Protons = Anion (-).


◉ Electrolytes.
Answer: Any substance that gives off or forms ions when dissolved
in water.