BIO 107 - EXAM #1 – CSUN QUESTIONS AND ANSWERS 100% SOLVED

BIO 107 - EXAM #1 – CSUN QUESTIONS AND ANSWERS 100% SOLVED All Matter including living organisms, are composed of: atoms and combinations of atoms Protons are: Positively charged particles located in the nucleus Neutrons are: uncharged particles located in the nucleus Electrons are: negatively charged particles found in orbitals surrounding the nucleus An Element is: a pure substance that cant be broken down into simpler components by ordinary chemical or physical techniques. Atoms combine chemically in fixed numbers and rations to form the: molecules Each atom consists of an atomic __________ surrounded by negatively-charged electrons Nucleus The number of protons in a nuclei are called the: atomic number The nuclei of all atoms also contain uncharged: neutrons mass number = (# of protons) + (# of neutrons) Isotopes are: distinct forms of atoms of an element with the same number of protons but different numbers of neutrons. Nuclei of some isotopes are unstable and break down giving off particles of matter and energy, this is: radioactivity The most important applications of radioisotopes are as labels or: tracers The region of space where an electron is found most frequently is its: orbital Orbitals make up: energy levels or electron shells electrons in an atoms outermost energy level are its: valence electrons