Answer:
Chemical science arises in the seventeenth century from the studies of alchemy popular among many of the scientists of the time. The basic principles of chemistry are considered to be collected for the first time in the work of the British scientist Robert Boyle: The Skeptical Chemist (1661).
Answer:
electrons
Explanation:
The photoelectric effect occurs when electrons are emitted from metal when the metal is struck by light of certain frequencies.
Some of the applications of this effect include photomultipliers (which are a key component in spectroscopy instruments) and night vision devices.
Atomic percentages<u>: 68% of copper and 32% of nickel.</u>
How this is calculated?
The given alloy is 100 g ,
m(Cu) = 0,7 · 100 g = 70 g.
m(Ni) = 0,3 · 100 g = 30 g.
n(Cu) = m(Cu) ÷ M(Cu) = 70 g ÷ 63,546 g/mol
n(Cu) = 1,10 mol.
n(Ni) = m(Ni) ÷ M(Ni) = 30 g ÷ 58,71 g/mol
n(Ni) = 0,51 mol
n(Cu) : n(Ni) = 1,10 mol : 0,51 mol
%(Cu) = 1,1 mol ÷ 1,61 mol = 0,68 = 68 %.
Similarly, %(Ni)=32%
What are Cu-Ni alloys?
- Cu-Ni alloys are alloys of copper (base metal with the largest individual content) and nickel with or without other elements, whereby the zinc content may not be more than 1%.
- When other elements are present, nickel has the largest individual content after copper, compared with each other element.
- As with other copper alloys, it is necessary to distinguish between wrought alloys, which are processed to semi-finished products, and cast alloys, from which castings are produced by various casting processes.
To know more about Cu-Ni alloys, refer:
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The chemical breakdown of enormous quantities of organic material buried in the sedimentary rocks has produced ethane gas.