A medium can be anything that a wave can pass through e.g the medium can be solid objects, air, water, etc.
A national day is a day on which celebrations mark the nationhood of a nation or state. It may be the date of independence, of becoming a republic, or a significant date for a patron saint or a ruler (such as a birthday, accession, or removal). The national day is often a public holiday.
Answer:
According to Le-chatelier principle, equilibrium will shift towards left to minimize concentration of 
and keep same equilibrium constant
Explanation:
In this buffer following equilibrium exists -
So, is involved in the above equilibrium.
When a strong base is added to this buffer, then concentration of increases. Hence, according to Le-chatelier principle, above equilibrium will shift towards left to minimize concentration of and keep same equilibrium constant.
Therefore excess amount of combines with 
to produce ammonia and water. So, effect of addition of strong base on pH of buffer gets minimized.
Sediment is solid material that is moved and deposited in a new location. Sediment can consist of rocks and minerals, as well as the remains of plants and animals. It can be as small as a grain of sand or as large as a boulder. Sediment moves from one place to another through the process of erosion.
What is likely to occur if sulfur forms an ionic bond with another element is <u>sulfur will accept electrons</u>
<u><em> explanation</em></u>
- Ionic bond is formed when a metal react with a non metal.
- Metal loses ( donate) electrons to form cation ( a positively charged ion) , while non metal accept (gain) electrons to form anion ( a negatively charged ion ).
- Sulfur is a non metal therefore it accept electrons if it form an ionic bond with a metal. sulfur accept 2 electrons to form S2- ion
