Answer: If the gold in the crown was mixed with a less-valuable metal such as bronze of copper then this affects its density by making it to weigh even more and if it weighs more then it has less of chance to float. Observe: Drag each of the crowns into the liquid.
Explanation:
 
        
             
        
        
        
1 and 3 only because metal are easily to loss electron while non metal are difficult to loss electron that's why it called heavy elements.
        
             
        
        
        
Answer: 22 kJ amount of energy is released in the following reaction.
Explanation: There are two types of reaction on the basis of amount of heat absorbed or released.
1. Endothermic reactions: These are the type of reactions in which reactants absorb heat to form the products. The energy of the reactants is less than the energy of the products.
2. Exothermic reactions: These are the type of reactions in which heat is released from the chemical reactions. The energy of the products is less than the reactants.
Sign convention for  : This value is negative for exothermic reactions and positive for endothermic reactions.
: This value is negative for exothermic reactions and positive for endothermic reactions.
For the given chemical reaction,
Energy of the products is less than the energy of the reactants, Hence, this reaction will be a type of exothermic reaction and energy will be released during this chemical change.
Amount of energy released = (350 - 372) kJ = -22kJ
Negative sign symbolizes the energy is being released. So, 22 kJ amount of energy is released in the following reaction.
 
        
             
        
        
        
Answer:

Explanation:
Hello there!
In this case, according to the Dalton's law, which explains that the total pressure of a gaseous system equals the sum of the partial pressures of the gases composing, for the gaseous mixture composed by oxygen, nitrogen and carbon dioxide it would be possible to write:

Now, given the pressure of the system and those of oxygen and nitrogen, we calculate that of carbon dioxide as shown below:

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