Question

question 10
which of the following is an ionic compound?
d.c3h8
a.co2
c.cao
b.nh3
question 11
how many valence electrons does s2- have?
a.8
b.6
c.16
d.4
question 12
group 1 elements will primarily
d lose two electrons
a gain one electron
c gain two electrons
b lose one electron

Explanation:

Step1: Recall ionic compound definition

Ionic compounds form from a metal and a non - metal. Ca (calcium) is a metal and O (oxygen) is a non - metal in CaO. CO2, NH3 and C3H8 are covalent compounds.

Step2: Recall valence electron concept for S²⁻

Sulfur (S) is in group 16 and has 6 valence electrons. S²⁻ has gained 2 electrons, so 6 + 2=8 valence electrons.

Step3: Recall Group 1 elements behavior

Group 1 elements have 1 valence electron and will lose this 1 electron to achieve a stable electron configuration.

Answer:

Question 10: C. CaO
Question 11: A. 8
Question 12: B. lose one electron