Answer: The best way to promote the process are:
--> Add a bit of solid as a seed crystal.
--> Scratch the bottom of the flask gently with a stirring rod.
Explanation:
A crystal growth is seen is SUPERSATURATED solutions which contains more solute than it can normally dissolve at that given temperature. It is usually very UNSTABLE and capable of releasing the excess solute if disturbed, either by shaking or seeding with a tiny crystals.
Crystallization can be used for the separation of two salts with different solubilities as well as for purification of a soluble salt that contains insoluble solid impurities. Recrystallization improves the validity of the process. Crystallization can be initiated by:
--> Scratching the bottom of the flask gently with a stirring rod: scratching initiates crystallization by providing energy from the high-frequency vibrations.
--> Adding a bit of solid as a seed crystal: Seed crystals create a nucleation site where crystals can begin growth.
Answer: 2.48×10^-17 J
Explanation:
Given the following :
Wavelength = 8nm (8 x 10^-9 m)
Energy(e) of X-ray =?
Energy=[speed of light(c) × planck's constant (h)] ÷ wavelength
Speed of light = 3×10^8m/s
Planck's constant = 6.626×10^-34 Js
Wavelength = 8 x 10^-9 m
Energy = [(3×10^8) * (6.626×10^-34)] / 8 x 10^-9
Energy = [19.878×10^(8-34)] / 8 x 10^-9
Energy = 2.48475 × 10^(-26+9)
Energy = 2.48×10^-17 J
Boil it. Kinetic energy is energy of motion and hot water moleculues move more
Answer:
10 kg of ice will require more energy than the released when 1 kg of water is frozen because the heat of phase transition increases as the mass increases.
Explanation:
Hello!
In this case, since the melting phase transition occurs when the solid goes to liquid and the freezing one when the liquid goes to solid, we can infer that melting is a process which requires energy to separate the molecules and freezing is a process that releases energy to gather the molecules.
Moreover, since the required energy to melt 1 g of ice is 334 J and the released energy when 1 g of water is frozen to ice is the same 334 J, if we want to melt 10 kg of ice, a higher amount of energy well be required in comparison to the released energy when 1 kg of water freezes, which is about 334000 J for the melting of those 10 kg of ice and only 334 J for the freezing of that 1 kg of water.
Best regards!
Answer:
The possible valances can be determined by electron configuration and electron negativity
Good Luck even though this was asked 2 weeks ago
Explanation:
All atoms strive for stability. The optima electron configuration is the electron configuration of the VIII A family or inert gases.
Look at the electron configuration of the nonmetal and how many more electrons the nonmetal needs to achieve the stable electron configuration of the inert gases. Non metals tend to be negative in nature and gain electrons. ( They are oxidizing agents)
For example Florine atomic number 9 needs one more electron to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Flowrine has a valance of -1
Oxygen atomic number 8 needs two more electrons to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Oxygen has a valance charge of -2.
Non metals with a low electron negativity will lose electrons when reacting with another non metal that has a higher electron negativity. When the non metal forms an ion it is necessary to look at the electron structure to determine how many electrons the element can lose to gain stability.
For example Chlorine which is normally -1 like Florine when it combines with oxygen can be +1, +3, + 5 or +7. It can lose its one unpaired electron, or combinations of the unpaired electron and sets of the three pairs of electrons.
