<em>Chemists use the mole unit to represent 6.022 × 10 23 things, whether the things are atoms of elements or molecules of compounds. This number, called Avogadro's number, is important because this number of atoms or molecules has the same mass in grams as one atom or molecule has in atomic mass units. </em>
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I just took the test it is A hope this helps :)
Answer:The correct answer is option C.
Explanation;
Water has unique property that is, it expands on freezing.Which is the reason for less density of ice than water. The cracking of the bottle was due to the expansion of water (present inside the bottle) on freezing.
Generally, density is inversely proportional to the volume of the substance.
As we know ,that water expands on freezing which means that volume increases. And with increase in volume of density decreases.
Hence, the correct answer is option C.
Answer:
The volume is 1.2L
Explanation:
Initial volume (V1) = 700mL = 0.7L
Initial temperature (T1) = 7°C = (7 + 273.15)K = 280.15K
Initial pressure = 106.6kPa = 106600Pa
Final temperature (T2) = 27°C = (27 + 273.15)K = 300.15K
Final pressure (P2) = 66.6kPa = 66600Pa
Final volume (V2) = ?
To solve this question, we need to use combined gas equation which is a combination of Boyle's law, Charles Law and pressure law.
(P1 × V1) / T1 = (P2 × V2) / T2
solve for V2 by making it the subject of formula,
P1 × V1 × T2 = P2 × V2 × T1
V2 = (P1 × V1 × T2) / (P2 × T1)
V2 = (106600 × 0.7 × 300.15) / (66600 × 280.15)
V2 = 22397193 / 18657990
V2 = 1.2L
The final volume of the gas is 1.2L
Answer:
Elements are pure substances which are composed of only one type of atom. Compound are substances which are formed by two or more different types of elements that are united chemically in fixed proportions. ... Some of the examples of elements are Iron, Copper, Gold, etc. A few examples of compounds are NaOH, NaCl, etc.
