For the forth time pls someone help with my homework

Which element in the third period would you expect to have the larger atomic radius, sodium (na) or sulfur (s)? a. sodium, because it has a higher effective nuclear charge attracting electrons in fewer energy levels. b. sodium, because it has fewer protons attracting electrons in the same energy levels. c. sulfur, because it has more protons attracting electrons in more energy levels. d. sulfur, because it has a higher effective nuclear charge attracting electrons in the same energy levels.

List four observations that indicate that a chemical reaction may be taking place

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?