1. True or false. a. Barium forms constant charge cations of 3+ charge. b. Cu+and Cu2+ are different ions and have different properties. c. CO and CO2 are isomers. d. Polyatomic ions contain covalent bonds. e. Ionic compounds are network compounds. 2. a. What is the formula of the monatomic ion which has 23 protons and 20 electrons? b. What is the formula of the monatomic ion which has 15 protons and 18 electrons? c. What is the formula of the monatomic ion which has 31 protons and 28 electrons? 3. a. How many electrons are in one Co3+ ion? b. How many electrons are in one Nb2+ ion? c. How many electrons are in one Brion? 4. a. What is the symbol for the element which forms a 2- monatomic anion containing 54 electrons? b. What is the symbol for the element which forms a 2 + monatomic cation containing 44 electrons? c. What is the symbol for the element which forms a 1+ monatomic cation containing 36 electrons