Question

what does tetra· mean?
1
2
3
4

1. choose the best answer.

____ compounds contain carbon and hydrogen.
organic
inorganic

1. choose the best answer.

what is the oxidation number of sulfur?
-2

Explanation:

Question 1: What does tetra - mean?

In chemistry (and general terminology), the prefix "tetra - " is a common prefix that means 4. For example, in a molecule like $CCl_4$ (carbon tetrachloride), the "tetra - " indicates that there are 4 chlorine atoms attached to the carbon atom.

By definition, organic compounds are compounds that contain carbon and hydrogen (along with other elements in many cases). Inorganic compounds generally do not have this characteristic (though there are some exceptions like carbonates, but the general definition of organic compounds centers around carbon - hydrogen bonds).

In many common compounds like hydrogen sulfide ($H_2S$) or metal sulfides (e.g., $Na_2S$), sulfur exists as the sulfide ion ($S^{2 - }$) where the oxidation number of sulfur is - 2. This is because sulfur has a tendency to gain 2 electrons to achieve a stable electron configuration (similar to the noble gas argon), resulting in an oxidation number of - 2.

Answer:

4 (the option with "4" as the text, assuming the options are numbered as 1, 2, 3, 4 with 4 being the correct one for the meaning of tetra - )

Question 19: ____ compounds contain carbon and hydrogen.