- Based on last term's topic, we found out that salt can both be useful and
harmful. Why is this so? (2 marks) - What is "hypnonatremia"? (1
mark) - Why do people say that it is impossible to drown in the Dead Sea? (1
mark) - There are two ways to harvest (get) salt. Name these two ways and explain
how salt is extracted. (4
marks) - During winter, salt is sprinkled on the snow. Why? (1 mark)
- Salt is a compound made of two elements. What are these elements? (2
marks) - What is "solution mining"
and how does it work? (2 marks) - What is a "sink hole" and
how is it formed? (2 marks)
Answers:
1. It is because salt can help our brain to send electirc signals or signals to other
parts of the body, but at the same time, too much salt will lead to sickness,
e.g water retention, and even fatal results.
2. Hypnonatremia is sodium concentration in the blood that is lower than normal.
3. It is because there are extremely high amount of salt in the dead sea, even more than
the amount of water, the salt is dissolved in the water and have a large
density, and other things have less density, so it will stay on top. The salt
will also stay there in the sea, it won't go, so there are plenty of them to
disslove.
4. Solution Mining and evaporation (getting salt from the sea). First, undergo solution
mining, the water is pumped down and dissolved some salts, the brine is then
pumped up again, then the water is evaporated to leave pure salt. For the
evaporation, the water is evaporated to get salt from the sea.
5. The salt in water will prevent ice from forming, because the water containing salt have a
lower freezing point.
6. Sodium and chlorine.
7. Solution mining is using water to mine the salt.
First, undergo solution mining, the water is pumped down and dissolved some salts, the
brine is then pumped up again, then the water is evaporated to leave pure salt.
8.The hole which caused by solution mining. The water dissolves more and more of the ground and the salt, which made the hole bigger and bigger, so finally, the ground
cannot support the things on top and will collapse, which leave a hole called
the sink hole.
![Picture](/uploads/1/0/7/9/10796332/5079795.jpg)
Can you see how harmful can solution mining cause?!