Answer:
Lesson Summary. A substance is simply a pure form of matter. In other words, a substance is matter than contains only one type of atom or molecule. Pure substances can be further divided into two sub-categories: elements and compounds.
Explanation:
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Answers with Explanations:
1. Why is knowledge of mineral properties important?
Knowledge of mineral properties is important because it <u>helps scientists know about the earth's history, particularly when it comes to "rock formations."</u> It is also essential in order to know which minerals are economically important.
2. Which properties might be useful in construction?
Minerals have many physical properties (<em>color, crystal form, hardness, luster, density, cleavage and fracture, etc.) </em>
When it comes to construction purpose, the mineral's malleability is very important. This is the reason why "iron" is one of the most important minerals being used in buildings. It's <em>malleability</em> allows it to be framed into "steel," which is then used to make even bigger infrastructures and skyscrapers.
3. In jewelry-making?
When it comes to "jewelry-making," the <em>hardness </em>and <em>luster</em> of the mineral may be used as a basis. For example, the diamond can be determined from the rest of the minerals because it is the hardest and it has a brilliant-kind of luster.
Answer: 2800 g
Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number
of particles.
Given mass = 5 kg = 5000 g
1 mole of
produces = 1 mole of 
50 moles of
produces =
of 
Mass of 
2800 g of
is produced from 5.0 kg of limestone.
Answer : The concentration of a solution with an absorbance of 0.420 is, 0.162 M
Explanation :
Using Beer-Lambert's law :

As per question, at constant path-length there is a direct relation between absorbance and concentration.

where,
A = absorbance of solution
C = concentration of solution
l = path length
= initial absorbance = 0.350
= final absorbance = 0.420
= initial concentration = 0.135 M
= final concentration = ?
Now put all the given value in the above relation, we get:


Thus, the concentration of a solution with an absorbance of 0.420 is, 0.162 M
A solid has definite volume and shape, a liquid has a definite volume but no definite shape, and a gas has neither a definite volume nor shape. ... (a) Solid O2 has a fixed volume and shape, and the molecules are packed tightly together.
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