Chem 120 Final| 100 Questions| With Complete Solutions

Significant Figure correct answer: a digit that is either reliably known or closely estimated conversion factors correct answer: relationship between two quantities expressed as a fraction (1 inch/2.45cm) element correct answer: the most basic form of matter that exists under ordinary condidtions compound correct answer: a unique, pure substance that is composed of two or more elements which are chemically combined atom correct answer: smallest fundamental particle of an element that has properties of that element Dalton's Atomic Theory correct answer: 1. Matter is composed of small indivisible particles called atoms 2. All atoms of the same element are identical and have the same properties 3. Chemical compounds are composed of atoms of different elements combined in whole number ratios 4. Chemical reactions are simply the rearrangement of atoms into different combinations atomic mass unit correct answer: convenient unit of measuring the masses of subatomic particles and atoms; equal to 1.67 x 10²⁴ g Atomic number correct answer: number of protons (number of electrons in a neutral atom) Helps to distinguish one element from another Mass number correct answer: total number of nucleons; distinguishes isotopes- atoms with the same number of protons but different numbers of neutrons Isotopic mass correct answer: mass of an atom relative to ¹²C (which is defined as exactly 12 aum atomic mass correct answer: a weighted average of the isotopic masses of all stable isotopes of an element Molecular compound correct answer: compound in which atoms are held together by covalent bonds (share electrons) Ionic compounds correct answer: compound in which atoms are held together by ionic bonds (exchange/transfer of electrons) Ion correct answer: atom that has an electrostatic charge cation correct answer: positively charged atom