Helium only possesses two valence electrons, while the other noble gasses posses eight
8. A. Density is independent of size (an intensive property).
9. B. The highest density is 1786 g/20cm^3, or 89.3 g/cm^3. The least is 512 g/20cm^3, or 25.6 g/cm^3. Therefore, the difference is 89.3 - 25.6, or 63.7 g/cm^3.
10. C. A bottle filled with air weighs less than one filled with marshmallows, because air is less dense than marshmallows.
11. D. The number represents the number of protons in the nucleus of the atom, as well as the atomic number of the element.
12. C. The number represents the atomic mass of the element, which is determined based on the relative abundance of each form of the element.
Option A is correct answer.
According to octet rule, atoms have tendency to lose, gain and share electrons to complete its octet i.e. eight valence electrons are surrounded to the atom.
Since, sulphur contains six valence electrons and two chlorine atoms are present in the reaction having seven valence electrons. Thus, to complete their octet, chlorine shares a pair of electrons with the sulphur atom.
Answer:
the particles they are made of