Answer:
Niels Bohr, refined the model of an atom by proposing a quantized shell structure atomic model in order to describe how the electrons are able to maintain stable orbits around the nucleus
Based on the predictions of classical mechanics the electron motion of the Rutherford model was unstable as the electrons where expected to have lost some energy during motion and thus having to come rest in the nucleus
According to the modification by Neils Bohr in 1913, electrons move in shells or orbits of fixed energy and emission of electromagnetic radiation takes place only when electrons changes the orbit in which they move
Explanation:
<u>Stimulants </u> often cause overactive eye movement
Ans (A)
Stimulants are a class of psychoactive drugs that increase the brain activity. They work by acting on the central nervous system and increase the level of mental alertness and impart heightened cognitive functions. Stimulants like nicotine and cocaine cause overactive eye movement.
Answer: A. Internal energy : May be viewed as the sum of the kinetic and potential energies of the molecules
B. Latent heat: The internal energy associated with the phase of a system.
C. Chemical (bond) energy : The internal energy associated with the atomic bonds in a molecule
D. Nuclear energy : The internal energy associated with the bonds within the nucleus of the atom itself
Explanation:
Internal energy is defined as the total energy of a closed system. Internal energy is the sum of potential energy of the system and the kinetic energy of the system. It is represented by symbol U.
Latent heat is the thermal energy released or absorbed by a thermodynamic system when the temperature of the system does not change. It is thus also called as hidden heat.
Chemical energy is the energy stored in the bonds of molecules.
Nuclear energy is the energy which is stored in the nucleus of an atom called as binding energy within protons and neutrons.
Answer:
Luster of aluminum is Silver-White.
Explanation:
Aluminium is a Silver-White metal which is extracted from the Bauxite ore which can be reddish brown, white, tan, grey-white and tan-yellow in color and have the minerals like Gibbsite, Boehmite and Diaspore which are the minerals of the aluminium.
The Bauxite is the rock from which the Bauxite ore is extracted which have the minerals of the aluminum.
The luster of a metal is the color and shine of it and its shiny appearance.
Aluminium is a light weight metal but have a moderate hardness which makes a wider use of it. Aluminium is used in many places where the weight of the material is kept light but its hardness can be increased by mixing some other metals in it making hard alloy with lighter weight.
It is used in transportation vehicles, buildings, and many other places like Air crafts as the weight should be kept controlled to give a perfect lift to the Air craft.
Answer:
1
Explanation:
For non metals to attain a noble gas configuration, they gain the number of electrons needed to attain the noble gas configuration of the noble gas at the end of their periods. This means that these non metals would only take up the configuration of the last element on their periods which of course is always a noble gas.
The last element on the hydrogen period or more conservatively the only other element on the hydrogen period is helium, with an atomic number of 2. The atomic number is the number of protons in he nucleus of an atom. For an electrically neutral atom, the number of electrons equal the number of protons.
Hence we can deduce that helium has 2 electrons while hydrogen has one electron. Thus for it to attain the configuration of helium, it just needs to gain one more electron
