<span>Answer: a mixture.
</span><span>Justification:</span>
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</span><span>1) Pure substances have a definite chemical formula: the same kind of atoms with the same fixed ratios and chemical bonds. Therefore, the percents of each element do not varye.
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2) Elements and compounds are pure substaces. For example, Fe, Mg, Ti, are elements, and CO₂, CO, H₂CO₃ are compounds. Each of them will have always the same kind of atoms, in the same ratio and with the same chemcial bonds. Therefore the percents of the elements do not varye.
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<span>3) Mixtures are formed by the physical combination (not chemical bonds) of different elements or compounds in variable proportions. As indicated, this describes the material bronze, in virtue of the variation of its composition. Other examples of mixtures are solutions (like brines), air, ocean water, and milk: different brines, different oceans and different milk have different contents of elements or compounds.
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Answer:
The minimum resistance is 25 ohms.
Explanation:
Resistance of each resistor is 100 ohms. When resistors are connected in parallel, the equivalent resistance is lowest. For parallel combination, the equivalent resistance is given by :
Here, all resistors are 100 ohms. So,
So, the minimum resistance is 25 ohms.
Question four is : Gaseous state
Question five is : A rise in temperature increases the kinetic energy and speed of particles; it does not weaken the forces between them. The particles in solids vibrate about fixed positions; even at very low temperatures. Individual particles in liquids and gases have no fixed positions and move chaotically.
Hope this helps!
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Answer:
The answer to your question is 58.7 g of Ca(OH)₂
Explanation:
Data
mass of Ca(OH)₂ = ?
mass of HNO₃ = 100 g
Process
1.- Write the balanced chemical reaction
Ca(OH)₂ + 2HNO₃ ⇒ Ca(NO₃)₂ + 2H₂O
2.- Calculate the molar mass of the reactants
Ca(OH)₂ = 40 + 32 + 2 = 74 g
HNO₃ = 1 + 14 + 48 = 63 g
3.- Use proportions to calculate the mass of Ca(OH)₂
74 g of Ca(OH)₂ ----------------- 2(63) g of HNO₃
x ----------------- 100 g of HNO₃
x = (100 x 74) / 2(63)
x = 7400 / 126
x = 58.7 g
Sodium (Na)
Founder is Humphry Davy
Discovery year is 1807
