<u>Answer:</u>
<em>Theoretical density values </em>
- brass-

- bronze-

- steel-

<u>Explanation:</u>
All of these substances are<em> </em>alloys (a substance made from melting two or more substances, one of them usually being a metal). Brass is a combination of copper and zinc, bronze is mostly copper, tin and other non-metals as well and steel is majorly made up of iron and copper. These alloys have various uses and varying importance in different kinds of industries.
Answer:
atomic number
Explanation:
isotope is a family of an element with the same atomic number but different mass number.
Out of the options, the best indicator is a color change since it is the only one that can't really be blamed on a physical change. you will eventually notice that during qualitative labs and some quantitative labs, usually the thing that you are looking for is either color change or the production of a precipitate to indicate the presence of a chemical reaction
Answer:
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Explanation:
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Answer:
The change in the internal energy of the system -878 J
Explanation:
Given;
energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)
Work done on the system, W = -311 J (negative because work was done on the system)
change in internal energy of the system, Δ U = ?
First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).
ΔU = Q - W
ΔU = -1189 - (-311)
ΔU = -1189 + 311
ΔU = -878 J
Therefore, the change in the internal energy of the system -878 J