A penny is made of a silver core with a copper coating. Although you can not see the sliver underneath, it is therefore, a homogenous mixture. It is an evenly distributed mixture of copper Cu, and Silver Ag.
The correct answer is: [A]:
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"Picture I shows a chemical change, because a new substance is formed."
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Note: "Picture II" is a "physical change" because it is a "phase change"—no "new substance" is form; rather, the same substance changes form.
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The equation to be used to
calculate the heat absorbed when solid melts is the enthalpy of melting. It is
represented as H
= mCpT where H is the heat
released after phase change, m is the mass of the substance, Cp is the specific
heat capacity of the substance and T
is the change in temperature.
H
= mCpT
H
= (18g/1000g/kg)(4.184kJ/kg-K)(293-(-263))
H
= 41.87kJ
Answer:
1. sensitive or sensitized to the action of radiant energy photosensitive paper. 2. being or caused by an abnormal reaction to sunlight photosensitive rashes.
Explanation:
hope this helps! ^w^
Answer:
Liquid water and ethanol are described as miscible because they <u>mutually dissolve each other in all proportions</u>.
Explanation:
Miscibility is defined as the property of two substances to mix each other in all proportions and make a homogenous mixture. This physical property is a reversible property and mainly depends upon the intermolecular interactions between the two substances.
Water: Water has a chemical formula H₂O, in which hydrogen atom is directly bonded to oxygen atom. Oxygen atom being more electronegative atom make the hydrogen partial negative and the oxygen itself becomes partial negative.
Ethanol: Ethanol has a chemical formula C₂H₅OH. In this molecule there is also the presence of O-H bond as that found in water and with the same partial negative charges.
Thus, the opposite partial charges of these molecules interact with each other and forms one of the strongest intermolecular bonds called as Hydrogen Bonds resulting in dissolution of each other in all proportions.
