Regents Chemistry Exam August 2022
Base your answers to questions 52 through 54 on the information below and on your knowledge of chemistry.
Fluorine, chlorine, bromine, and iodine are located in Group 17 and are called halogens.
52 State, in terms of electrons, why these halogens have similar chemical properties. 
Whenever the questions says "state in terms of", we must use the terms they are asking about. Halogens are all in the same group (column) on the Periodic Table. This means they all have the same number of valence electrons (electrons in the outermost shell).
Answer: Halogens have similar chemical properties because they have the same number of valence electrons.
53. Compare the radius of a chlorine atom to the radius of a Cl- ion. 
A minus charge signifies an addition of one electron. Remember, electrons are negatively charged.
Answer: The radius of chlorine atom is smaller than the radius of Cl- ion.
54 In the space in your answer booklet, draw a Lewis electron-dot diagram for an atom of fluorine in the ground state. 
First we need to figure out how many valence electrons Fluorine has. The electron configuration for Fluorine on the Periodic table is 2-7. The last number is the number of valence electrons = 7. Alternatively, because fluorine is in group 17, it has 7 valence electrons. Now, we need to distribute seven electrons around the element symbol.