Answer:
A new Dana system of classification contains 78 different classes of minerals based on composition and then further classified by type and group. To be considered a mineral, a substance must be an inorganic, naturally formed solid, with a specific chemical formula and a fixed internal structure. To test whether something is a mineral, there are several identification tests to which the substance is subjected, including its resistance to scratching, its density in comparison to water, its color, the degree of light it reflects, the color of the powdered mineral, its breakage pattern and its crystalline form.
Explanation:
Answer:
Organisms need to take food to get energy and perform life processes. A living organism undergoes many life processes like nutrition, respiration, digestion, transportation, excretion, circulation of blood, and reproduction. To perform all these life processes the organism needs energy and nutrients.
Explanation:
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Answer:
<u><em>PLEASE SHOW ME THE ELEMENTS OR I WOULD ENLIST ALL THE ELEMENTS.</em></u>
Explanation:
Group 6A (or VIA) of the periodic table are the chalcogens: the nonmetals oxygen (O), sulfur (S), and selenium (Se), the metalloid tellurium (Te), and the metal polonium (Po)
Answer:

Explanation:
Using the Ideal Gas Law we have
and the number of moles n could be expressed as
, where m is the mass and M is the molar mass.
Now, replacing the number of moles in the equation for the ideal gass law:

If we pass the V to divide:

As the density is expressed as
, we have:

Solving for the density:

Then we need to convert the units to the S.I.:






Finally we replace the values:




First convert to moles:
0.5113 g / 17 g/mol = 0.0301 mol
Now create a ratio based on the reaction provided to solve for the unknown:
4 NH3 / -905.4 kJ = 0.0301 mol NH3 / x kJ
x = -6.808 kJ