BIO 181 NAU- Exam 1 Questions and Answers Solved 100% Correct!!

Matter - Anything that occupies space and has a mass Three Physical States of Matter - Solid, liquid, gas Element - Substance that cannot be broken down into other substances by chemical reactions Four elements that make up about 96% of the weight and most cells: - Oxygen, carbon, hydrogen, nitrogen Atoms - The smallest functional units of matter that form ALL chemical substances Three subatomic particles - Protons, Neutrons, Electrons Protons - Positive charge, found in nucleus. Number of protons is what distinguishes one element from another Atomic number - How many protons are in an element Mass number - sum of the number of protons and neutrons in its nucleus Isotopes - Forms of an element with different numbers of neutrons than protons. Ex; Carbon 12 = 6 protons and 7 neutrons. Gaining vs. Losing electrons - N+1 = Losing electron N-1 = Gaining electron Electrons = electronegativeOctet rule - Atoms are most stable when their outer shell is full. The outer shell has to be filled with 8 electrons EXCEPT Hydrogen and Helium with just 2 electrons. Valence Electrons - Electrons more likely to form bonds, taken away, or shared with other atoms. Electrons in the outer shell Compounds - Putting two elements together Two types of chemical bonds - Ionic and covalent Ionic Bonds - ELECTRON SWAP- formed between oppositely charged ions. Ex; NaCl Ions (2 types) - Charged atoms Cations: Have a net positive charge (+) Anions: Have a net negative charge (-) Ionic - Something with a charge Covalent Bond - Forms when two atoms SHARE one or more pairs of outer-shell electrons. These bonds are the strongest of bonds. Polar Molecules - An uneven distribution of charge Ex; H2O. Hydrogen are slightly positive, oxygen is slightly negative. Hydrogen Bond - A weak attraction between a partially positive hydrogen and a partially negative atom like Oxygen. Causes cohesion Cohesion - The tendency of molecules of the same kind to stick together. Ex; sipping through a straw. In order for the water to be sucked up and stuck together is cohesionHeat - The amount of energy associated wit hteh movement of the atoms and molecules in a body of matter Temperature - Measures the intensity of heat