Answer:
Explanation:
Half time is period required to desintegrating the half of the initial number of atoms. Then, the total time is:
A volcanic arc is a chain of volcanoes formed above a subducting plate, positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc.
Despite its appearance, air has a ‘thickness’ so when the sun is high in the sky the light travels through the air on a very much shorter path than when it is low on the horizon.
Imagine that air water and you are below the surface, the light from an overhead sun will be quite sharp and bright, but if lower in the sky it will have to travel through much more water to reach you, so will look less bright and sharp. It ma not seem the same, but the atmosphere is just like very thin water, and a low lying sun will be drastically reduced in strength, so all you will see is a sun with a shift to the red end of the spectrum as all the actinic part will be filtered away by that thicker atmosphere.
When Br2 and NaF are mixed, no reaction would occur since Br cannot replace F in NaF which gives NaBr + F₂ as products. Hence, Fluorine is more reactive than Bromine. Hence, Br can't replace F.
<u>Explanation</u>:
- When two reactants Br2 and NaF are mixed, no reaction takes place since Br cannot replace F in NaF. By seeing the periodic table, the positions of the halogens in the periodic table, bromine is located way below fluorine.
- Bromine will not have sufficient energy to replace fluorine and so it will not have energy which is sufficient to join because of low reactivity. Among these fluorine represents the most reactive element among halogens.
- Some of you may think it is a single replacement reaction that gives NaBr + F₂ as products. But, according to the halogen reactivity, it decreases from top to down of the group. F is placed above Br. Hence, Fluorine is more reactive than Bromine. Hence, Br can't replace F.
