All you can conclude is that something must be burning with an orange flame.
Actually, the "something" that must be burning is the hydrogen that is produced when the sodium reacts with the water:
2Na + 2H₂O → 2NaOH + H₂ + heat
So much heat is produced that the hydrogen catches fire and some of the sodium evaporates into the flame.
The electrons in the sodium atoms get "excited" in the flame. When they drop back to a lower energy level, they emit energy in the form of an orange-yellow light.
Answer:
The correct answer is - D. It gets rid of pathogens that invade the body.
Explanation:
Like all other organ systems, the immune system is an organ system that involves several special organs that helps in fighting any foreign object or infection that invades our body. This organ system produces specific cells or chemicals to fight or kill the microbes, and unnatural change takes place in the body.
The organs involved in the immune system are lymphocytes or white blood cells, the complement system, antibodies, the lymphatic system the thymus, bone marrow, and the spleen.
All these combinedly helps in fighting, killing the microbes or infections that occur in the body, and correct the physiological changes that occur in the body to get rid of pathogens that invade the body.
Ni(OH)₂ ⇄ Ni⁺² + 2 OH⁻
Ksp = [Ni⁺²][OH⁻]² = S (2S)² = 4S³
where S is molar solubility.
at pH = 10
[H⁺] = 10⁻¹⁰
[H⁺][OH⁻] = 10⁻¹⁴
so [OH⁻] = 10⁻⁴ M
Ksp = S [10⁻⁴ + 2S]²
Ksp is very small so the molar solubility of OH⁻ will be very small
so (10⁻⁴ + 2S) is about 10⁻⁴
so Ksp = S x 10⁻⁸
S =
= 6 x 10⁻⁸ M
“An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt). Groundwater can be extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology.”
Wikipedia › wiki › Aquifer
I hope this helps
