Elements of Group 1 and group 2 in the periodic
table contain elements so reactive that they are never found in the free state
<u>Explanation</u>:
The metals in group 1 of periodic table consisting of 'alkali metals' which include lithium, potassium, sodium, rubidium, Francium and caesium. They are highly reactive because they have low ionisation energy and larger radius. The group 2 metals consist of 'alkaline earth metals' which include calcium, strontium, barium, beryllium, radium and magnesium. These alkaline earth metal have +2 oxidation number, hence are highly reactive.
These both group metals are mostly reactive and so are never found in a free state. When they are exposed to air they would immediately react with oxygen. Hence, are stored in oils to avoid oxidation.
Steel is practically one of the worlds most important metals to use in construction, it is harder and stronger than iron can be. You can say iron is the base metal of steel, if you need more info, just ask :>
Answer:
CFC’s illustrate that technical advances can be a “double-edged” sword as CFC's were made for the advantages but soon or later it came as a disadvantage for environment.
CFC's was discovered with many advantages such as they are stable, non-corrosive, and replacement of harmful ammonia used in refrigerators and air conditioning systems. But soon it is also discovered that CFC's are destroying the upper atmosphere layer called ozone, which is a very big disadvantage for us. CFCs are major contributor to global warming after carbon dioxide.
Hence, it proves that CFC’s shows how technological advancement can be “double-edged” sword.
Answer:
Filtering <span>is best laboratory technique to separate a solid from a liquid to recover the liquid.
Explanation:
A solid particles present in liquids can be separated from liquid by utilizing a membrane having pores large enough to allow the liquid molecules to pass through and small enough to stop the solid particles from crossing.
Example:
Tea Filters are used to separate Tea from the grounds.
Kidney is an excellent example of Biological Filter.
</span><span>Whatman Cellulose Filter Paper used in Chemistry Labs.</span>
