Question

11) Helium has an atomic number of 2. stable atom? (0.5pt) Why is this element considered a chemically inert or 12) Which of the following molecules is an inorganic molecule? (0.5pt): a) CHE b) Sucrose c) Naci d) Triglyceride 13) A student prepares a chemical solution with a pH of 8. If the solution prepared is buffered (meaning it contains a buffer to maintain the solution at pH 8) how with the buffer act to maintain this pH? (1pt)

Answer 1

11. Helium atomic number = 2
Electron configuration = 1s2
Elements whose outer shells are completely occupied tend to be chemically stable and unreactive i.e. inert.
The maximum number of electrons possible in the first shell = 2
Number of electrons found in He = 2
Hence Helium is an inert element even though it does not possess octet configuration.

12. Option C is correct
In general, compounds that contain carbon are considered organic molecules.
Methane, sucrose, and triglycerides are organic molecules.
NaCl is an inorganic molecule. It is an ionic compound.

13. Buffers = Solutions that resist a moderate change in their pH
Buffers neutralize any added base or acid to maintain a stable pH