Answer:
The correct answer is option C.
Explanation:
Single replacement reaction : It is a type of chemical reaction in which element exchange their position with the position of another element in its compound molecule.

It is also called redox reaction because one element getting oxidized and another one getting reduced.
Hence, the correct answer is option C.
To get the number of gold atoms, you have to divide the mass of the gold by the mass of the gold atom. It follows this simple equation

.
Let x be the number of gold atoms. Plug in the values to a calculator.
x =

Both have the same units so the unit gram(g) can be cancelled.
x then would be equal to 1.53x10^22. So there are 1.53x10^22 atoms of gold in 5 g of gold
Answer:
If gas is cooled the particles will then stop moving about really fast and start to form a liquid. This is called condensation.. (i think) and it happens at the same amount of temperature as or when boiling. Evaporation is dependent on individual particles gaining enough energy to escape the surface of the liquid and become gas particles.
Another comment: Can you please look at my question? I really need help as well.
Also use this website for more help on these questions its called states of matter: basics
C because we need materials in the lab