We write DE = q+w, where DE is the internal energy change and q and w are heat and work, respectively.
(b)Under what conditions will the quantities q and w be negative numbers?
q is negative when heat flows from the system to the surroundings, and w is negative when the system does work on the surroundings.
As an aside: In applying the first law, do we need to measure the internal energy of a system? Explain.
The absolute internal energy of a system cannot be measured, at least in any practical sense. The internal energy encompasses the kinetic energy of all moving particles in the system, including subatomic particles, as well as the electrostatic potential energies between all these particles. We can measure the change in internal energy (DE) as the result of a chemical or physical change, but we cannot determine the absolute internal energy of either the initial or the final state. The first law allows us to calculate the change in internal energy during a transformation by calculating the heat and work exchanged between the system and its surroundings.
Answer:Figure 1. Energy losses in an incandescent light bulb are very large; most of the input energy is lost in the form of heat energy. This means that when energy is converted to a different form, some of the input energy is turned into a highly disordered form of energy, like heat. ...
Explanation:
C.<span>The effort force is most often smaller than the force needed without the machine.</span>
Answer:
1) chemical property
2) physical property
3) chemical property
4) physical property
Explanation:
Physical properties:
Physical properties are those properties which can be measured without changing the composition of mater. We can observe the object and tell its physical properties like its texture, physical appearance, color, melting point, boiling point, odor, density etc.
Chemical properties:
Chemical properties involve chemical reaction or we can say that change is happen in mater during chemical reaction and the properties, we measured during this or as a result of this reaction is called chemical properties. Like flammability, toxicity, combustion, decomposition etc.
1) Water can split into hydrogen and oxygen
chemical property
2) water is liquid at room temperature
physical property
3) water react with certain metals
chemical property
4)The density of water is 1.0 g/cm³
physical property
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Answer</u>
:</h2>
N and C
<h2>_____________________________________</h2><h3><u>WHY OPTION A?</u></h3>
Because Lithium and Sodium belong to group 1A whereas Magnesium is from group 2A, which are S block elements and they form ionic bond.
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