Answer: The coefficient is 3.645
The exponent is 1
There are 4 significant digits
The rightmost significant figure is 5
Explanation:
Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.
For example : 5000 is written as 
According to avogadro's law, 1 mole of every gas contains avogadro's number
of particles, occupy 22.4 L at STP and weighs equal to its molecular mass.
131.29 g of Xe occupy = 22.4 L at STP.
Thus 213.62 g of
occupy =
at STP.
Scientific notation = 
The coefficient is 3.645
The exponent is 1
There are 4 significant digits
The rightmost significant figure is 5
Question 1:
(a) Sulfurous acid: H2SO3
Sulfuric acid: H2SO4
(b) Nitrous acid: H2NO2
Nitric acid: H2NO3
Question 2:
To calculate the pH, based on concentration of H+ ions, there is one formula:

So the pH of this solution is

(the solution is basic).
Answer:
The most important ore of aluminum is<u> Bauxite.</u>
And its chemical formula is
.
Explanation:
Bauxite is the most important ore of Aluminium from which Aluminium is extracted. Bauxite is a rock and composed of Aluminium bearing mineral.
And its chemical formula is
.
It contains Gibbsite, Bohmite and Diaspore along with iron.
It is a soft material with somewhat white to grey to reddish brown in colour.
It has an earthy lustre and low specific gravity.
<u />
Scoria
Explanation:
Scoria is a rock that is commonly made up of gas bubbles and minerals such as hornblende, muscovite, olivine, lucite and or plagioclase.
Scoria is an extrusive igneous rock with a lot of cavities and vesicles indicating gas bubbles.
- Scoria is product of basaltic magma.
- It has nearly the same composition as basalt since it originates from it.
- They silica deficient and very fine grained with holes in them.
- The holes shows channels by which trapped gases are forcefully ejected out.
- They are usually found associated with cindercone volcanoes.
learn more:
Volcanoes brainly.com/question/5055821
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